Hi Jeff,
So I took a moment and generated those CSV files and a small markup. Of
course it is subject for manual review of what should be or shouldn't be
sent over a real inter-domain EBGP session.
I generated a complete list and permit only approach.
It is highly amazing how much "stuff" carried by BGP today is not
recommended to be used inter-domain !!!
If WGs especially those on the front lines think this makes sense to
review, publish and keep updating as we add more stuff to BGP I think this
can be done quite easily.
I am not sure if the right home for this would be IDR or GROW :)
Cheers,
Robert
PS. Route-Refresh as mentioned can also be further dissected for ORF drop
if given vendor's policy allows.
On Sat, May 23, 2026 at 2:44 PM Jeffrey Haas <[email protected]> wrote:
> I'm supportive of a "filter by default" registry. Presuming that the
> encoding is simple enough, it probably could live in IANA and be maintained
> as part of community allocation.
>
> -- Jeff
> On 5/23/26 07:33, Robert Raszuk wrote:
>
> Hi Mikael,
>
> > There are vendors that don't by default do this and I doubt they'll
>
> Indeed !
>
> And I think today it may actually not be that easy to accurately construct
> a filtering policy for EBGP peers.
>
> So with that IDR & GROW WGs (cc-ed) would fill about publishing on IDR or
> GROW wiki a csv file which would contain all attributes and communities
> which should be by default filtered on EBGP boundary (unless otherwise
> overwritten by operator for reasons like same admin domain as example)?
>
> It may be way easier than trying to analyze all drafts, temporary
> allocations and published rfc every day.
>
> It could be used as:
>
> * always up to date hint to the operator
> * direct import to NOS
> * input to AI to construct your BGP policy
>
> The format of such a csv file could be documented in a draft/rfc.
>
> It could be updated each time there is some new IANA allocation made in
> any of the BGP registry and adjusted when allocation changes.
>
> Alternatively it could be done outside of IETF (RIPE, NANOG etc ...) but
> then maintenance of it may be a bit harder.
>
> I think it also fits Jeff's attribute escape umbrella as one of the
> possible tools in the BGP toolkit.
>
> Thx,
> Robert
>
>
> On Sat, May 23, 2026 at 6:42 AM Mikael Abrahamsson <swmike=
> [email protected]> wrote:
>
>> On Fri, 22 May 2026, Keyur Patel wrote:
>>
>> > * In both cases, this filtering MUST be enabled by default for EBGP
>> sessions.
>>
>> There are vendors that don't by default do this and I doubt they'll
>> change, so then the next-best I can see is clear operational
>> recommendations to operators on what to do at their border, and at least
>> that the vendors have an easy way to achieve this.
>>
>> Right now I have one vendor that doesn't seem to make it easy to "filter
>> all extended communities on border".
>>
>> --
>> Mikael Abrahamsson email: [email protected]
>>
>> _______________________________________________
>> Idr mailing list -- [email protected]
>> To unsubscribe send an email to [email protected]
>>
>
> _______________________________________________
> Idr mailing list -- [email protected]
> To unsubscribe send an email to [email protected]
>
> _______________________________________________
> Idr mailing list -- [email protected]
> To unsubscribe send an email to [email protected]
>
message_type,attribute_type,attribute_trans,sub-type,sub-type_trans,send|drop
OPEN,,N/A,type=1,N/A,send
UPDATE,,N/A,type=2,N/A,send
NOTIFICATION,,N/A,type=3,N/A,send
KEEPALIVE,,N/A,type=4,N/A,send
ROUTE-REFRESH,,N/A,type=5,N/A,send
UPDATE,1 ORIGIN,well-known mandatory; transitive (speaker forwards if recognized),,,send
UPDATE,2 AS_PATH,well-known mandatory; transitive,,,send
UPDATE,3 NEXT_HOP,well-known mandatory; transitive (NEXT_HOP rewrite per RFC4271 §5.1.3),,,send
UPDATE,6 ATOMIC_AGGREGATE,well-known discretionary; transitive,,,send
UPDATE,14 MP_REACH_NLRI,optional non-transitive (RFC4760),,,send
UPDATE,15 MP_UNREACH_NLRI,optional non-transitive (RFC4760),,,send
UPDATE,17 AS4_PATH,optional transitive (RFC6793),,,send
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFFFF01 NO_EXPORT,AS-scope export policy,send
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFFFF02 NO_ADVERTISE,AS-scope,send
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFFFF03 NO_EXPORT_SUBCONFED,confederation-scope,send
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFFFF04 NOPEER,peer-scope (RFC3765),send
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFF029A BLACKHOLE,operational signaling (RFC7999),send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=1 Multiprotocol Extensions,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=2 Route Refresh,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=5 Extended Next Hop Encoding,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=6 BGP Extended Message,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=9 BGP Role,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=64 Graceful Restart,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=65 4-octet AS number,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=69 ADD-PATH,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=70 Enhanced Route Refresh,session capability,send
message_type,attribute_type,attribute_trans,sub-type,sub-type_trans,send|drop
OPEN,,N/A,type=1,N/A,send
UPDATE,,N/A,type=2,N/A,send
NOTIFICATION,,N/A,type=3,N/A,send
KEEPALIVE,,N/A,type=4,N/A,send
ROUTE-REFRESH,,N/A,type=5,N/A,send
UPDATE,1 ORIGIN,well-known mandatory; transitive (speaker forwards if recognized),,,send
UPDATE,2 AS_PATH,well-known mandatory; transitive,,,send
UPDATE,3 NEXT_HOP,well-known mandatory; transitive (NEXT_HOP rewrite per RFC4271 §5.1.3),,,send
UPDATE,4 MULTI_EXIT_DISC,optional non-transitive (RFC4271),,,drop
UPDATE,5 LOCAL_PREF,well-known discretionary; non-transitive (iBGP only),,,drop
UPDATE,6 ATOMIC_AGGREGATE,well-known discretionary; transitive,,,send
UPDATE,7 AGGREGATOR,optional transitive (deprecated practice),,,drop
UPDATE,8 COMMUNITIES,optional transitive (RFC1997); value semantics AS-local/private,,,drop
UPDATE,9 ORIGINATOR_ID,optional non-transitive (RFC4456),,,drop
UPDATE,10 CLUSTER_LIST,optional non-transitive (RFC4456),,,drop
UPDATE,11 DPA (deprecated),deprecated,,,drop
UPDATE,12 ADVERTISER (historic) (deprecated),deprecated,,,drop
UPDATE,13 RCID_PATH / CLUSTER_ID (Historic) (deprecated),deprecated,,,drop
UPDATE,14 MP_REACH_NLRI,optional non-transitive (RFC4760),,,send
UPDATE,15 MP_UNREACH_NLRI,optional non-transitive (RFC4760),,,send
UPDATE,16 EXTENDED COMMUNITIES,optional transitive (RFC4360); extcomm type/sub-type transit in high octet,,,drop
UPDATE,17 AS4_PATH,optional transitive (RFC6793),,,send
UPDATE,18 AS4_AGGREGATOR,optional transitive (RFC6793),,,drop
UPDATE,19 SAFI Specific Attribute (SSA) (deprecated),deprecated,,,drop
UPDATE,20 Connector Attribute (deprecated),deprecated,,,drop
UPDATE,21 AS_PATHLIMIT (deprecated),deprecated,,,drop
UPDATE,22 PMSI_TUNNEL,optional transitive (RFC6514),,,drop
UPDATE,23 Tunnel Encapsulation,optional transitive (RFC9012),,,drop
UPDATE,24 Traffic Engineering,optional transitive (RFC5543),,,drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701),,,drop
UPDATE,26 AIGP,optional transitive (RFC7311),,,drop
UPDATE,27 PE Distinguisher Labels,optional transitive (RFC6514),,,drop
UPDATE,28 BGP Entropy Label Capability Attribute (deprecated),deprecated,,,drop
UPDATE,29 BGP-LS Attribute,optional non-transitive (RFC9552),,,drop
UPDATE,30 Deprecated,deprecated,,,drop
UPDATE,31 Deprecated,deprecated,,,drop
UPDATE,32 LARGE_COMMUNITY,optional non-transitive (RFC8092),,,drop
UPDATE,33 BGPsec_Path,optional non-transitive (RFC8205),,,drop
UPDATE,"34 BGP Community Container Attribute (TEMPORARY - registered 2017-07-28, extension registered 2024-08-22, expires 2025-07-28)",see defining RFC (optional/transitive per attribute flags),,,drop
UPDATE,35 Only to Customer (OTC),optional non-transitive (RFC9234),,,drop
UPDATE,36 BGP Domain Path (D-PATH),optional transitive (draft/RFC EVPN interworking),,,drop
UPDATE,37 SFP attribute,optional transitive (RFC9015),,,drop
UPDATE,38 BFD Discriminator,optional transitive (RFC9026),,,drop
UPDATE,"39 BGP Next Hop Dependent Characteristic (NHC) (TEMPORARY - registered 2022-12-20, extension registered 2025-11-24, expires 2026-12-20)",see defining RFC (optional/transitive per attribute flags),,,drop
UPDATE,40 BGP Prefix-SID,optional transitive (RFC8669),,,drop
UPDATE,41 BIER,optional transitive (RFC9793),,,drop
UPDATE,"42 Edge Metadata Path Attribute (TEMPORARY - registered 2025-04-23, extension registered 2026-04-03, expires 2027-04-23)",see defining RFC (optional/transitive per attribute flags),,,drop
UPDATE,128 ATTR_SET,optional transitive (RFC6368),,,drop
UPDATE,129 Deprecated,deprecated,,,drop
UPDATE,241 Deprecated,deprecated,,,drop
UPDATE,242 Deprecated,deprecated,,,drop
UPDATE,243 Deprecated,deprecated,,,drop
UPDATE,255 Reserved for development,see defining RFC (optional/transitive per attribute flags),,,drop
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFF0000 GRACEFUL_SHUTDOWN,AS-scope policy,drop
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFF0001 ACCEPT_OWN,AS-scope (RFC7611),drop
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFFFF01 NO_EXPORT,AS-scope export policy,send
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFFFF02 NO_ADVERTISE,AS-scope,send
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFFFF03 NO_EXPORT_SUBCONFED,confederation-scope,send
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFFFF04 NOPEER,peer-scope (RFC3765),send
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFF029A BLACKHOLE,operational signaling (RFC7999),send
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFF0006 LLGR_STALE,graceful restart (RFC9494),drop
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFF0007 NO_LLGR,graceful restart (RFC9494),drop
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0xFFFF0009 Standby PE,MPLS/VPN (RFC9026),drop
UPDATE,8 COMMUNITIES,optional transitive; community value AS-scope,0x00010000-0xFFFEFFFF Private Use (ASN:local),AS-scope per RFC1997,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x00 MAC Mobility,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x01 ESI Label,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x02 ES-Import Route Target,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x03 EVPN Router’s MAC Extended Community,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x04 EVPN Layer 2 Attributes,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x05 E-Tree Extended Community,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x06 DF Election Extended Community,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x08 ARP/ND Extended Community,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x09 Multicast Flags Extended Community,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x0A EVI-RT Type 0,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x0B EVI-RT Type 1,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x0C EVI-RT Type 2,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x0D EVI-RT Type 3,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x0E EVPN Attachment Circuit Extended Community,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x0F Service Carving Time,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x10 EVPN Link Bandwidth Extended Community,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x06 subtype=0x15 RT-derived-EC,transitive (type 0x06),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x00 subtype=0x02 Route Target,transitive (type 0x00),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x00 subtype=0x03 Route Origin,transitive (type 0x00),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x00 subtype=0x04 Link Bandwidth,transitive (type 0x00),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x00 subtype=0x05 OSPF Domain Identifier,transitive (type 0x00),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x00 subtype=0x06 Route Aggregation Parameter,transitive (type 0x00),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x00 subtype=0x08 BGP Data Collection,transitive (type 0x00),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x00 subtype=0x09 Source AS,transitive (type 0x00),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x00 subtype=0x0a L2VPN Identifier,transitive (type 0x00),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x00 subtype=0x10 Cisco VPN-Distinguisher,transitive (type 0x00),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x00 subtype=0x13 Route-Target Record,transitive (type 0x00),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x00 subtype=0x15 RT-derived-EC,transitive (type 0x00),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x00 subtype=0x80 Virtual-Network Identifier Extended Community,transitive (type 0x00),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x40 subtype=0x04 Link Bandwidth,non-transitive (type 0x40),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x40 subtype=0x80 Virtual-Network Identifier Extended Community,non-transitive (type 0x40),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x02 subtype=0x02 Route Target,transitive (type 0x02),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x02 subtype=0x03 Route Origin,transitive (type 0x02),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x02 subtype=0x04 Generic (deprecated),transitive (type 0x02),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x02 subtype=0x05 OSPF Domain Identifier,transitive (type 0x02),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x02 subtype=0x06 Route Aggregation Parameter,transitive (type 0x02),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x02 subtype=0x08 BGP Data Collection,transitive (type 0x02),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x02 subtype=0x09 Source AS,transitive (type 0x02),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x02 subtype=0x10 Cisco VPN Identifier,transitive (type 0x02),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x02 subtype=0x13 Route-Target Record,transitive (type 0x02),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x02 subtype=0x15 RT-derived-EC,transitive (type 0x02),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x42 subtype=0x04 Generic (deprecated),non-transitive (type 0x42),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x02 Route Target,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x03 Route Origin,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x04 IPv4-Address-Specific IFIT Tail Community,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x05 OSPF Domain Identifier,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x07 OSPF Route ID,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x09 Node Target Extended Community,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x0a L2VPN Identifier,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x0b VRF Route Import,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x0c Flow-spec Redirect to IPv4,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x10 Cisco VPN-Distinguisher,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x12 Inter-Area P2MP Segmented Next-Hop,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x13 Route-Target Record,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x14 VRF-Recursive-Next-Hop-Extended-Community,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x15 RT-derived-EC,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x01 subtype=0x20 MVPN SA RP-address Extended Community,transitive (type 0x01),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x41 subtype=0x09 Node Target Extended Community,non-transitive (type 0x41),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x01 Cost Community,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x03 CP-ORF,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x04 Extranet Source Extended Community,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x05 Extranet Separation Extended Community,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x06 OSPF Route Type,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x07 Additional PMSI Tunnel Attribute Flags,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x08 Context-Specific Label Space ID Extended Community,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x09 UPA Extended Community,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x0b Color Extended Community,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x0c Encapsulation Extended Community,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x0d Default Gateway,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x0e Point-to-Point-to-Multipoint (PPMP) Label,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x0f BGP Group Policy Class Tag Extended Community,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x10 Site Identifier Extended Community,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x14 Consistent Hash Sort Order,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x17 Group Policy ID Extended Community,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0x1b Local Color Mapping (LCM),transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x03 subtype=0xaa LoadBalance,transitive (type 0x03),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x43 subtype=0x00 BGP Origin Validation State Extended Community,non-transitive (type 0x43),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x43 subtype=0x01 Cost Community,non-transitive (type 0x43),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x43 subtype=0x02 Route Target,non-transitive (type 0x43),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x43 subtype=0x15 RT-derived-EC,non-transitive (type 0x43),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x80 subtype=0x00 OSPF Route Type (deprecated),transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x80 subtype=0x01 OSPF Router ID (deprecated),transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x80 subtype=0x04 SecurityGroup,transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x80 subtype=0x05 OSPF Domain Identifier (deprecated),transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x80 subtype=0x06 Flow spec traffic-rate-bytes,transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),"type=0x80 subtype=0x07 Flow spec traffic-action (Use of the ""Value"" field is defined in the ""Traffic Action Fields"" registry)",transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x80 subtype=0x08 Flow spec rt-redirect AS-2octet format,transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x80 subtype=0x09 Flow spec traffic-remarking,transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x80 subtype=0x0a Layer2 Info Extended Community,transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x80 subtype=0x0b E-Tree Info,transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x80 subtype=0x0c Flow spec traffic-rate-packets,transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x80 subtype=0x0d Flow Specification for SFC Classifiers,transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x80 subtype=0x84 Tag,transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x80 subtype=0x85 Origin Sub-Cluster,transitive (type 0x80 generic),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x81 subtype=0x08 Flow spec rt-redirect IPv4 format,transitive (type 0x81),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x82 subtype=0x04 SecurityGroupAS4,transitive (type 0x82),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x82 subtype=0x08 Flow spec rt-redirect AS-4octet format,transitive (type 0x82),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x82 subtype=0x84 Tag4,transitive (type 0x82),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x82 subtype=0x85 Origin Sub-Cluster4,transitive (type 0x82),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x0b subtype=1 SFIR Pool Identifier,transitive (type 0x0b),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x0b subtype=2 MPLS Label Stack Mixed Swapping/Stacking Labels,transitive (type 0x0b),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x0a subtype=0x02 Route Target,transitive (type 0x0a),drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive; extcomm type defines transit (RFC7153),type=0x4a subtype=0x02 Route Target,non-transitive (type 0x4a),drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701); 2-octet type field,type=0x0002 Route Target,"transitive (IPv6-address-specific, RFC5701/7153)",drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701); 2-octet type field,type=0x0003 Route Origin,"transitive (IPv6-address-specific, RFC5701/7153)",drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701); 2-octet type field,type=0x0004 OSPFv3 Route Attributes (deprecated),"transitive (IPv6-address-specific, RFC5701/7153)",drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701); 2-octet type field,type=0x0005 IPv6-Address-Specific IFIT Tail Community,"transitive (IPv6-address-specific, RFC5701/7153)",drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701); 2-octet type field,type=0x0006 Extension of Link Bandwidth Extended Community,"transitive (IPv6-address-specific, RFC5701/7153)",drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701); 2-octet type field,type=0x000b VRF Route Import,"transitive (IPv6-address-specific, RFC5701/7153)",drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701); 2-octet type field,type=0x000c Flow-spec Redirect to IPv6,"transitive (IPv6-address-specific, RFC5701/7153)",drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701); 2-octet type field,type=0x000d Flow spec rt-redirect-ipv6 format,"transitive (IPv6-address-specific, RFC5701/7153)",drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701); 2-octet type field,type=0x0010 Cisco VPN-Distinguisher,"transitive (IPv6-address-specific, RFC5701/7153)",drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701); 2-octet type field,type=0x0011 UUID-based Route Target,"transitive (IPv6-address-specific, RFC5701/7153)",drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701); 2-octet type field,type=0x0012 Inter-Area P2MP Segmented Next-Hop,"transitive (IPv6-address-specific, RFC5701/7153)",drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701); 2-octet type field,type=0x0014 VRF-Recursive-Next-Hop-Extended-Community,"transitive (IPv6-address-specific, RFC5701/7153)",drop
UPDATE,25 IPv6 Address Specific Extended Community,optional transitive (RFC5701); 2-octet type field,type=0x0015 RT-derived-EC,"transitive (IPv6-address-specific, RFC5701/7153)",drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x04 QoS Marking,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x05 CoS Capability,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x07 FlowSpec Transitive Extended Communities,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x08 Flow spec redirect/mirror to IP next-hop,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x09 FlowSpec Redirect to indirection-id,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x0c SRv6 MUP Extended Community,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x44 QoS Marking (non-transitive),non-transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x47 FlowSpec Non-Transitive Extended Communities,non-transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x04 QoS Marking,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x05 CoS Capability,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x07 FlowSpec Transitive Extended Communities,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x08 Flow spec redirect/mirror to IP next-hop,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x09 FlowSpec Redirect to indirection-id Extended Community,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x0a Transport Class,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x0c SRv6 MUP Extended Community,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x83-0x8f Reserved for Experimental Use,transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x44 QoS Marking,non-transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x47 FlowSpec Non-Transitive Extended Communities,non-transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0x4a Non-Transitive Transport Class,non-transitive,drop
UPDATE,16 EXTENDED COMMUNITIES,optional transitive,type=0xc0-0xcf Reserved for Experimental Use,non-transitive,drop
UPDATE,BGP Prefix-SID,optional transitive (RFC8669),bgp-prefix-sid-tlv-types:1 Label-Index,inherits attribute,drop
UPDATE,BGP Prefix-SID,optional transitive (RFC8669),bgp-prefix-sid-tlv-types:2 Deprecated,inherits attribute,drop
UPDATE,BGP Prefix-SID,optional transitive (RFC8669),bgp-prefix-sid-tlv-types:3 Originator SRGB,inherits attribute,drop
UPDATE,BGP Prefix-SID,optional transitive (RFC8669),bgp-prefix-sid-tlv-types:4 Deprecated,inherits attribute,drop
UPDATE,BGP Prefix-SID,optional transitive (RFC8669),bgp-prefix-sid-tlv-types:5 SRv6 L3 Service TLV,inherits attribute,drop
UPDATE,BGP Prefix-SID,optional transitive (RFC8669),bgp-prefix-sid-tlv-types:6 SRv6 L2 Service TLV,inherits attribute,drop
UPDATE,BGP Prefix-SID,optional transitive (RFC8669),bgp-prefix-sid-tlv-types:7 SRv6 Transport TLV,inherits attribute,drop
UPDATE,SFP attribute,optional transitive (RFC9015),sfp-attribute-tlvs:1 Association TLV,inherits attribute,drop
UPDATE,SFP attribute,optional transitive (RFC9015),sfp-attribute-tlvs:2 Hop TLV,inherits attribute,drop
UPDATE,SFP attribute,optional transitive (RFC9015),sfp-attribute-tlvs:3 SFT TLV,inherits attribute,drop
UPDATE,SFP attribute,optional transitive (RFC9015),sfp-attribute-tlvs:4 MPLS Swapping/Stacking,inherits attribute,drop
UPDATE,SFP attribute,optional transitive (RFC9015),sfp-attribute-tlvs:5 SFP Traversal With MPLS,inherits attribute,drop
UPDATE,BIER,optional transitive (RFC9793),bgp-bier-tlv-sub-tlv-types:1 BIER TLV,inherits attribute,drop
UPDATE,BIER,optional transitive (RFC9793),bgp-bier-tlv-sub-tlv-types:2 MPLS Encapsulation sub-TLV,inherits attribute,drop
UPDATE,BIER,optional transitive (RFC9793),bgp-bier-tlv-sub-tlv-types:3 non-MPLS Encapsulation sub-TLV,inherits attribute,drop
UPDATE,BIER,optional transitive (RFC9793),bgp-bier-tlv-sub-tlv-types:4 BIER Nexthop sub-TLV,inherits attribute,drop
UPDATE,BIER,optional transitive (RFC9793),bgp-bier-tlv-sub-tlv-types:5 BIER PHP Request,inherits attribute,drop
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=1 Multiprotocol Extensions,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=2 Route Refresh,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=3 Outbound Route Filtering,session capability,drop
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=5 Extended Next Hop Encoding,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=6 BGP Extended Message,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=7 BGPsec Capability,session capability,drop
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=9 BGP Role,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=64 Graceful Restart,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=65 4-octet AS number,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=69 ADD-PATH,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=70 Enhanced Route Refresh,session capability,send
OPEN,Capabilities (optional parameter 2),"N/A (negotiation, not propagated in UPDATE)",code=71 Long-Lived Graceful Restart,session capability,drop
# BGP Types, Sub-Types, and Transitiveness
Generated: 2026-05-23
Sources:
- [IANA BGP Parameters](https://www.iana.org/assignments/bgp-parameters/bgp-parameters.xhtml) (updated 2026-04-03)
- [IANA BGP Extended Communities](https://www.iana.org/assignments/bgp-extended-communities/bgp-extended-communities.xhtml) (updated 2026-05-19)
- [IANA BGP Well-known Communities](https://www.iana.org/assignments/bgp-well-known-communities/bgp-well-known-communities.xhtml)
- [IANA Capability Codes](https://www.iana.org/assignments/capability-codes/capability-codes.xhtml)
- Defining RFCs cited per row
## How to read this catalog
| Column | Meaning |
|--------|---------|
| `message_type` | BGP message (OPEN, UPDATE, …) or context |
| `attribute_type` | Path attribute code/name, OPEN parameter, or capability |
| `attribute_trans` | **Per BGP speaker** transitiveness for path attributes (RFC 4271 §4.3 flags and attribute-specific RFCs). `N/A` for non-UPDATE fields. |
| `sub-type` | Registry sub-type (extended community type/sub-type, community value, TLV, capability code, …) |
| `sub-type_trans` | For extended communities, transitiveness is encoded in the **type high-order octet** (RFC 4360 / RFC 7153): types `0x00–0x3f` and `0x80–0x82` are transitive; `0x40–0x7f` non-transitive. Community **values** are AS-scope policy. |
| `send\|drop` | **Operational recommendation** for default handling at an AS boundary when the attribute was designed for single-administration or overlay networks: **send** = safe default to allow toward eBGP peers for global unicast routing; **drop** = strip/filter by default at eBGP unless explicit policy enables it. |
### Transitiveness model (summary)
1. **BGP path attributes** — Transitive bit and optional/well-known class are defined per attribute in RFC 4271 and extensions. A speaker **must not** forward unrecognized optional transitive attributes; unrecognized optional non-transitive attributes are dropped locally and not propagated.
2. **Extended communities** — The first octet of the 8-octet extended community encodes transitive (`0x00–0x3F`, `0x80–0x82`) vs non-transitive (`0x40–0x7F`, `0x4A`, …) per RFC 7153. VPN Route Targets and similar sub-types are transitive on the wire but are operationally **AS-scoped**.
3. **Large communities** — Attribute is **optional non-transitive** (RFC 8092); semantics are always AS-local.
4. **Capabilities** — Negotiated in OPEN only; not subject to UPDATE transitiveness.
### Default `send|drop` philosophy
Recommendations assume a **multi-AS Internet edge** (provider, IX, or enterprise peering), not an iBGP-only or single-AS VPN core. Core DF attributes (`ORIGIN`, `AS_PATH`, `NEXT_HOP`, `MP_REACH/UNREACH_NLRI`) default to **send**. Attributes used for VPNs, EVPN, FlowSpec, SR, BFD, multicast, BGP-LS, and most communities default to **drop** at eBGP unless you operate that service end-to-end.
### Attribute vs sub-type rows (permit-list semantics)
- A row **without** `sub-type` describes the **whole path attribute** default.
- Rows **with** `sub-type` are finer-grained exceptions (e.g. a well-known community value).
- If every sub-type for an attribute is **drop**, the attribute row is also **drop** (strip the entire attribute). Example: **EXTENDED COMMUNITIES** — transitive on the wire per RFC 4360, but no sub-type is permitted at a default Internet edge.
- **COMMUNITIES**: attribute defaults to **drop**; only enumerated well-known values (NO_EXPORT, BLACKHOLE, …) appear as **send** sub-type rows. Implement as value-filtering, not blanket community export.
- The [permit CSV](bgp-types-transitiveness-permit.csv) contains only **send** rows: implicit **deny** for everything else.
Machine-readable exports:
- Full catalog: [`bgp-types-transitiveness.csv`](bgp-types-transitiveness.csv)
- Permit list (`send` only): [`bgp-types-transitiveness-permit.csv`](bgp-types-transitiveness-permit.csv)
---
## OPEN — Capabilities and optional parameters
| attribute_type | attribute_trans | sub-type | sub-type_trans | send|drop | reference |
|----------------|-----------------|----------|----------------|---------|-----------|
| | N/A | type=1 | N/A | **send** | RFC4271 |
## BGP message types (RFC 4271)
| attribute_type | attribute_trans | sub-type | sub-type_trans | send|drop | reference |
|----------------|-----------------|----------|----------------|---------|-----------|
| | N/A | type=2 | N/A | **send** | RFC4271 |
| | N/A | type=3 | N/A | **send** | RFC4271 |
| | N/A | type=4 | N/A | **send** | RFC4271 |
| | N/A | type=5 | N/A | **send** | RFC4271 |
## UPDATE — Path attributes (IANA BGP Path Attributes)
| attribute_type | attribute_trans | sub-type | sub-type_trans | send|drop | reference |
|----------------|-----------------|----------|----------------|---------|-----------|
| 1 ORIGIN | well-known mandatory; transitive (speaker forwards if recognized) | | | **send** | [RFC4271] |
| 2 AS_PATH | well-known mandatory; transitive | | | **send** | [RFC4271] |
| 3 NEXT_HOP | well-known mandatory; transitive (NEXT_HOP rewrite per RFC4271 §5.1.3) | | | **send** | [RFC4271] |
| 4 MULTI_EXIT_DISC | optional non-transitive (RFC4271) | | | **drop** | [RFC4271] |
| 5 LOCAL_PREF | well-known discretionary; non-transitive (iBGP only) | | | **drop** | [RFC4271] |
| 6 ATOMIC_AGGREGATE | well-known discretionary; transitive | | | **send** | [RFC4271] |
| 7 AGGREGATOR | optional transitive (deprecated practice) | | | **drop** | [RFC4271] |
| 8 COMMUNITIES | optional transitive (RFC1997); value semantics AS-local/private | | | **drop** | [RFC1997] |
| 9 ORIGINATOR_ID | optional non-transitive (RFC4456) | | | **drop** | [RFC4456] |
| 10 CLUSTER_LIST | optional non-transitive (RFC4456) | | | **drop** | [RFC4456] |
| 11 DPA (deprecated) | deprecated | | | **drop** | [Chen, E., Bates, T., "Destination Preference Attribute for |
| 12 ADVERTISER (historic) (deprecated) | deprecated | | | **drop** | [RFC1863][RFC4223][RFC6938] |
| 13 RCID_PATH / CLUSTER_ID (Historic) (deprecated) | deprecated | | | **drop** | [RFC1863][RFC4223][RFC6938] |
| 14 MP_REACH_NLRI | optional non-transitive (RFC4760) | | | **send** | [RFC4760] |
| 15 MP_UNREACH_NLRI | optional non-transitive (RFC4760) | | | **send** | [RFC4760] |
## UPDATE — Extended community types and sub-types
| attribute_type | attribute_trans | sub-type | sub-type_trans | send|drop | reference |
|----------------|-----------------|----------|----------------|---------|-----------|
| 16 EXTENDED COMMUNITIES | optional transitive (RFC4360); extcomm type/sub-type transit in high o | | | **drop** | [Eric_Rosen][draft-ramachandra-bgp-ext-communities-00][RFC43 |
## UPDATE — Path attributes (IANA BGP Path Attributes)
| attribute_type | attribute_trans | sub-type | sub-type_trans | send|drop | reference |
|----------------|-----------------|----------|----------------|---------|-----------|
| 17 AS4_PATH | optional transitive (RFC6793) | | | **send** | [RFC6793] |
| 18 AS4_AGGREGATOR | optional transitive (RFC6793) | | | **drop** | [RFC6793] |
| 19 SAFI Specific Attribute (SSA) (deprecated) | deprecated | | | **drop** | [Gargi_Nalawade][draft-kapoor-nalawade-idr-bgp-ssa-00][draft |
| 20 Connector Attribute (deprecated) | deprecated | | | **drop** | [RFC6037] |
| 21 AS_PATHLIMIT (deprecated) | deprecated | | | **drop** | [draft-ietf-idr-as-pathlimit-02] |
| 22 PMSI_TUNNEL | optional transitive (RFC6514) | | | **drop** | [RFC6514] |
| 23 Tunnel Encapsulation | optional transitive (RFC9012) | | | **drop** | [RFC9012] |
| 24 Traffic Engineering | optional transitive (RFC5543) | | | **drop** | [RFC5543] |
## UPDATE — IPv6-specific extended community (path attribute 25)
| attribute_type | attribute_trans | sub-type | sub-type_trans | send|drop | reference |
|----------------|-----------------|----------|----------------|---------|-----------|
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701) | | | **drop** | [RFC5701] |
## UPDATE — Path attributes (IANA BGP Path Attributes)
| attribute_type | attribute_trans | sub-type | sub-type_trans | send|drop | reference |
|----------------|-----------------|----------|----------------|---------|-----------|
| 26 AIGP | optional transitive (RFC7311) | | | **drop** | [RFC7311] |
| 27 PE Distinguisher Labels | optional transitive (RFC6514) | | | **drop** | [RFC6514] |
| 28 BGP Entropy Label Capability Attribute (deprecated) | deprecated | | | **drop** | [RFC6790][RFC7447] |
| 29 BGP-LS Attribute | optional non-transitive (RFC9552) | | | **drop** | [RFC9552] |
| 30 Deprecated | deprecated | | | **drop** | [RFC8093] |
| 31 Deprecated | deprecated | | | **drop** | [RFC8093] |
| 32 LARGE_COMMUNITY | optional non-transitive (RFC8092) | | | **drop** | [RFC8092] |
| 33 BGPsec_Path | optional non-transitive (RFC8205) | | | **drop** | [RFC8205] |
| 34 BGP Community Container Attribute (TEMPORARY - registered 2017-07-28, extension registered 2024-08-22, expires 2025-07-28) | see defining RFC (optional/transitive per attribute flags) | | | **drop** | [draft-ietf-idr-wide-bgp-communities-11] |
| 35 Only to Customer (OTC) | optional non-transitive (RFC9234) | | | **drop** | [RFC9234] |
| 36 BGP Domain Path (D-PATH) | optional transitive (draft/RFC EVPN interworking) | | | **drop** | [RFC-ietf-bess-evpn-ipvpn-interworking-18] |
| 37 SFP attribute | optional transitive (RFC9015) | | | **drop** | [RFC9015] |
| 38 BFD Discriminator | optional transitive (RFC9026) | | | **drop** | [RFC9026] |
| 39 BGP Next Hop Dependent Characteristic (NHC) (TEMPORARY - registered 2022-12-20, extension registered 2025-11-24, expires 2026-12-20) | see defining RFC (optional/transitive per attribute flags) | | | **drop** | [draft-ietf-idr-nhc-00] |
| 40 BGP Prefix-SID | optional transitive (RFC8669) | | | **drop** | [RFC8669] |
| 41 BIER | optional transitive (RFC9793) | | | **drop** | [RFC9793] |
| 42 Edge Metadata Path Attribute (TEMPORARY - registered 2025-04-23, extension registered 2026-04-03, expires 2027-04-23) | see defining RFC (optional/transitive per attribute flags) | | | **drop** | [draft-ietf-idr-5g-edge-service-metadata-27] |
| 128 ATTR_SET | optional transitive (RFC6368) | | | **drop** | [RFC6368] |
| 129 Deprecated | deprecated | | | **drop** | [RFC8093] |
| 241 Deprecated | deprecated | | | **drop** | [RFC8093] |
| 242 Deprecated | deprecated | | | **drop** | [RFC8093] |
| 243 Deprecated | deprecated | | | **drop** | [RFC8093] |
| 255 Reserved for development | see defining RFC (optional/transitive per attribute flags) | | | **drop** | [RFC2042] |
## UPDATE — Well-known and private-use communities
| attribute_type | attribute_trans | sub-type | sub-type_trans | send|drop | reference |
|----------------|-----------------|----------|----------------|---------|-----------|
| 8 COMMUNITIES | optional transitive; community value AS-scope | 0xFFFF0000 GRACEFUL_SHUTDOWN | AS-scope policy | **drop** | IANA bgp-well-known-communities |
| 8 COMMUNITIES | optional transitive; community value AS-scope | 0xFFFF0001 ACCEPT_OWN | AS-scope (RFC7611) | **drop** | IANA bgp-well-known-communities |
| 8 COMMUNITIES | optional transitive; community value AS-scope | 0xFFFFFF01 NO_EXPORT | AS-scope export policy | **send** | IANA bgp-well-known-communities |
| 8 COMMUNITIES | optional transitive; community value AS-scope | 0xFFFFFF02 NO_ADVERTISE | AS-scope | **send** | IANA bgp-well-known-communities |
| 8 COMMUNITIES | optional transitive; community value AS-scope | 0xFFFFFF03 NO_EXPORT_SUBCONFED | confederation-scope | **send** | IANA bgp-well-known-communities |
| 8 COMMUNITIES | optional transitive; community value AS-scope | 0xFFFFFF04 NOPEER | peer-scope (RFC3765) | **send** | IANA bgp-well-known-communities |
| 8 COMMUNITIES | optional transitive; community value AS-scope | 0xFFFF029A BLACKHOLE | operational signaling (RFC7999) | **send** | IANA bgp-well-known-communities |
| 8 COMMUNITIES | optional transitive; community value AS-scope | 0xFFFF0006 LLGR_STALE | graceful restart (RFC9494) | **drop** | IANA bgp-well-known-communities |
| 8 COMMUNITIES | optional transitive; community value AS-scope | 0xFFFF0007 NO_LLGR | graceful restart (RFC9494) | **drop** | IANA bgp-well-known-communities |
| 8 COMMUNITIES | optional transitive; community value AS-scope | 0xFFFF0009 Standby PE | MPLS/VPN (RFC9026) | **drop** | IANA bgp-well-known-communities |
| 8 COMMUNITIES | optional transitive; community value AS-scope | 0x00010000-0xFFFEFFFF Private Use (ASN:local) | AS-scope per RFC1997 | **drop** | IANA bgp-well-known-communities |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x00 MAC Mobility | transitive (type 0x06) | **drop** | RFC7432 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x01 ESI Label | transitive (type 0x06) | **drop** | RFC7432 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x02 ES-Import Route Target | transitive (type 0x06) | **drop** | RFC7432 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x03 EVPN Router’s MAC Extended Community | transitive (type 0x06) | **drop** | RFC9135 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x04 EVPN Layer 2 Attributes | transitive (type 0x06) | **drop** | RFC8214 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x05 E-Tree Extended Community | transitive (type 0x06) | **drop** | RFC8317 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x06 DF Election Extended Community | transitive (type 0x06) | **drop** | RFC8584;RFC9785 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x08 ARP/ND Extended Community | transitive (type 0x06) | **drop** | RFC9047 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x09 Multicast Flags Extended Community | transitive (type 0x06) | **drop** | RFC9251 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x0A EVI-RT Type 0 | transitive (type 0x06) | **drop** | RFC9251 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x0B EVI-RT Type 1 | transitive (type 0x06) | **drop** | RFC9251 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x0C EVI-RT Type 2 | transitive (type 0x06) | **drop** | RFC9251 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x0D EVI-RT Type 3 | transitive (type 0x06) | **drop** | RFC9251 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x0E EVPN Attachment Circuit Extended Community | transitive (type 0x06) | **drop** | draft-sajassi-bess-evpn-ac-aware-bundling-00 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x0F Service Carving Time | transitive (type 0x06) | **drop** | RFC9722 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x10 EVPN Link Bandwidth Extended Community | transitive (type 0x06) | **drop** | RFC-ietf-bess-evpn-unequal-lb-35 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x06 subtype=0x15 RT-derived-EC | transitive (type 0x06) | **drop** | draft-zzhang-idr-rt-derived-community-00 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x00 subtype=0x02 Route Target | transitive (type 0x00) | **drop** | RFC4360 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x00 subtype=0x03 Route Origin | transitive (type 0x00) | **drop** | RFC4360 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x00 subtype=0x04 Link Bandwidth | transitive (type 0x00) | **drop** | RFC-ietf-idr-link-bandwidth-23 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x00 subtype=0x05 OSPF Domain Identifier | transitive (type 0x00) | **drop** | RFC4577 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x00 subtype=0x06 Route Aggregation Parameter | transitive (type 0x00) | **drop** | Enke_Chen |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x00 subtype=0x08 BGP Data Collection | transitive (type 0x00) | **drop** | RFC4384 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x00 subtype=0x09 Source AS | transitive (type 0x00) | **drop** | RFC6514 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x00 subtype=0x0a L2VPN Identifier | transitive (type 0x00) | **drop** | RFC6074 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x00 subtype=0x10 Cisco VPN-Distinguisher | transitive (type 0x00) | **drop** | Eric_Rosen |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x00 subtype=0x13 Route-Target Record | transitive (type 0x00) | **drop** | draft-ietf-bess-service-chaining-00 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x00 subtype=0x15 RT-derived-EC | transitive (type 0x00) | **drop** | draft-zzhang-idr-rt-derived-community-00 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x00 subtype=0x80 Virtual-Network Identifier Extended Community | transitive (type 0x00) | **drop** | Manju_Ramesh |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x40 subtype=0x04 Link Bandwidth | non-transitive (type 0x40) | **drop** | RFC-ietf-idr-link-bandwidth-23 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x40 subtype=0x80 Virtual-Network Identifier Extended Community | non-transitive (type 0x40) | **drop** | draft-drao-bgp-l3vpn-virtual-network-overlays-03 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x02 subtype=0x02 Route Target | transitive (type 0x02) | **drop** | RFC5668 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x02 subtype=0x03 Route Origin | transitive (type 0x02) | **drop** | RFC5668 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x02 subtype=0x04 Generic (deprecated) | transitive (type 0x02) | **drop** | draft-ietf-idr-as4octet-extcomm-generic-subtype-10 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x02 subtype=0x05 OSPF Domain Identifier | transitive (type 0x02) | **drop** | RFC4577 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x02 subtype=0x06 Route Aggregation Parameter | transitive (type 0x02) | **drop** | Enke_Chen |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x02 subtype=0x08 BGP Data Collection | transitive (type 0x02) | **drop** | RFC4384 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x02 subtype=0x09 Source AS | transitive (type 0x02) | **drop** | RFC6514 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x02 subtype=0x10 Cisco VPN Identifier | transitive (type 0x02) | **drop** | Eric_Rosen |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x02 subtype=0x13 Route-Target Record | transitive (type 0x02) | **drop** | draft-ietf-bess-service-chaining-00 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x02 subtype=0x15 RT-derived-EC | transitive (type 0x02) | **drop** | draft-zzhang-idr-rt-derived-community-00 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x42 subtype=0x04 Generic (deprecated) | non-transitive (type 0x42) | **drop** | draft-ietf-idr-as4octet-extcomm-generic-subtype-10 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x02 Route Target | transitive (type 0x01) | **drop** | RFC4360 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x03 Route Origin | transitive (type 0x01) | **drop** | RFC4360 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x04 IPv4-Address-Specific IFIT Tail Community | transitive (type 0x01) | **drop** | draft-wang-idr-bgp-ifit-capabilities-02 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x05 OSPF Domain Identifier | transitive (type 0x01) | **drop** | RFC4577 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x07 OSPF Route ID | transitive (type 0x01) | **drop** | RFC4577 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x09 Node Target Extended Community | transitive (type 0x01) | **drop** | draft-ietf-idr-node-target-ext-comm-01 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x0a L2VPN Identifier | transitive (type 0x01) | **drop** | RFC6074 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x0b VRF Route Import | transitive (type 0x01) | **drop** | RFC6514 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x0c Flow-spec Redirect to IPv4 | transitive (type 0x01) | **drop** | draft-ietf-idr-flowspec-redirect-ip-02 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x10 Cisco VPN-Distinguisher | transitive (type 0x01) | **drop** | Eric_Rosen |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x12 Inter-Area P2MP Segmented Next-Hop | transitive (type 0x01) | **drop** | RFC7524 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x13 Route-Target Record | transitive (type 0x01) | **drop** | draft-ietf-bess-service-chaining-00 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x14 VRF-Recursive-Next-Hop-Extended-Community | transitive (type 0x01) | **drop** | Dhananjaya_Rao |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x15 RT-derived-EC | transitive (type 0x01) | **drop** | draft-zzhang-idr-rt-derived-community-00 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x01 subtype=0x20 MVPN SA RP-address Extended Community | transitive (type 0x01) | **drop** | RFC9081 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x41 subtype=0x09 Node Target Extended Community | non-transitive (type 0x41) | **drop** | draft-ietf-idr-node-target-ext-comm-01 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x01 Cost Community | transitive (type 0x03) | **drop** | draft-ietf-idr-custom-decision-04 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x03 CP-ORF | transitive (type 0x03) | **drop** | RFC7543 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x04 Extranet Source Extended Community | transitive (type 0x03) | **drop** | RFC7900 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x05 Extranet Separation Extended Community | transitive (type 0x03) | **drop** | RFC7900 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x06 OSPF Route Type | transitive (type 0x03) | **drop** | RFC4577 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x07 Additional PMSI Tunnel Attribute Flags | transitive (type 0x03) | **drop** | RFC7902 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x08 Context-Specific Label Space ID Extended Community | transitive (type 0x03) | **drop** | RFC9573 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x09 UPA Extended Community | transitive (type 0x03) | **drop** | draft-krierhorn-idr-upa-02 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x0b Color Extended Community | transitive (type 0x03) | **drop** | RFC9012 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x0c Encapsulation Extended Community | transitive (type 0x03) | **drop** | RFC9012 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x0d Default Gateway | transitive (type 0x03) | **drop** | Yakov_Rekhter |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x0e Point-to-Point-to-Multipoint (PPMP) Label | transitive (type 0x03) | **drop** | Rishabh_Parekh |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x0f BGP Group Policy Class Tag Extended Community | transitive (type 0x03) | **drop** | Dhananjaya_Rao |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x10 Site Identifier Extended Community | transitive (type 0x03) | **drop** | Renato_Fischer |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x14 Consistent Hash Sort Order | transitive (type 0x03) | **drop** | draft-ietf-bess-service-chaining-00 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x17 Group Policy ID Extended Community | transitive (type 0x03) | **drop** | draft-wlin-bess-group-policy-id-extended-community-02 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0x1b Local Color Mapping (LCM) | transitive (type 0x03) | **drop** | RFC9871 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x03 subtype=0xaa LoadBalance | transitive (type 0x03) | **drop** | draft-ietf-bess-service-chaining-05 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x43 subtype=0x00 BGP Origin Validation State Extended Community | non-transitive (type 0x43) | **drop** | RFC8097 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x43 subtype=0x01 Cost Community | non-transitive (type 0x43) | **drop** | draft-ietf-idr-custom-decision-04 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x43 subtype=0x02 Route Target | non-transitive (type 0x43) | **drop** | Nischal_Sheth |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x43 subtype=0x15 RT-derived-EC | non-transitive (type 0x43) | **drop** | draft-zzhang-idr-rt-derived-community-00 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x00 OSPF Route Type (deprecated) | transitive (type 0x80 generic) | **drop** | RFC4577 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x01 OSPF Router ID (deprecated) | transitive (type 0x80 generic) | **drop** | RFC4577 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x04 SecurityGroup | transitive (type 0x80 generic) | **drop** | Anantharamu_Suryanarayana;https://github.com/Juniper/contrai |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x05 OSPF Domain Identifier (deprecated) | transitive (type 0x80 generic) | **drop** | RFC4577 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x06 Flow spec traffic-rate-bytes | transitive (type 0x80 generic) | **drop** | RFC8955 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x07 Flow spec traffic-action (Use of the "Value" field is def | transitive (type 0x80 generic) | **drop** | RFC8955 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x08 Flow spec rt-redirect AS-2octet format | transitive (type 0x80 generic) | **drop** | RFC8955 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x09 Flow spec traffic-remarking | transitive (type 0x80 generic) | **drop** | RFC8955 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x0a Layer2 Info Extended Community | transitive (type 0x80 generic) | **drop** | RFC4761 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x0b E-Tree Info | transitive (type 0x80 generic) | **drop** | RFC7796 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x0c Flow spec traffic-rate-packets | transitive (type 0x80 generic) | **drop** | RFC8955 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x0d Flow Specification for SFC Classifiers | transitive (type 0x80 generic) | **drop** | RFC9015 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x84 Tag | transitive (type 0x80 generic) | **drop** | Anantharamu_Suryanarayana;https://github.com/Juniper/contrai |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x80 subtype=0x85 Origin Sub-Cluster | transitive (type 0x80 generic) | **drop** | Richard_Roberts;https://github.com/robric/wiki-contrail-cont |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x81 subtype=0x08 Flow spec rt-redirect IPv4 format | transitive (type 0x81) | **drop** | RFC8955 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x82 subtype=0x04 SecurityGroupAS4 | transitive (type 0x82) | **drop** | Anantharamu_Suryanarayana;https://github.com/Juniper/contrai |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x82 subtype=0x08 Flow spec rt-redirect AS-4octet format | transitive (type 0x82) | **drop** | RFC8955 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x82 subtype=0x84 Tag4 | transitive (type 0x82) | **drop** | Anantharamu_Suryanarayana;https://github.com/Juniper/contrai |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x82 subtype=0x85 Origin Sub-Cluster4 | transitive (type 0x82) | **drop** | Richard_Roberts;https://github.com/robric/wiki-contrail-cont |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x0b subtype=1 SFIR Pool Identifier | transitive (type 0x0b) | **drop** | RFC9015 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x0b subtype=2 MPLS Label Stack Mixed Swapping/Stacking Labels | transitive (type 0x0b) | **drop** | RFC9015 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x0a subtype=0x02 Route Target | transitive (type 0x0a) | **drop** | RFC9832 |
| 16 EXTENDED COMMUNITIES | optional transitive; extcomm type defines transit (RFC7153) | type=0x4a subtype=0x02 Route Target | non-transitive (type 0x4a) | **drop** | RFC9832 |
## UPDATE — IPv6-specific extended community (path attribute 25)
| attribute_type | attribute_trans | sub-type | sub-type_trans | send|drop | reference |
|----------------|-----------------|----------|----------------|---------|-----------|
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701); 2-octet type field | type=0x0002 Route Target | transitive (IPv6-address-specific, RFC5701/7153) | **drop** | RFC5701 |
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701); 2-octet type field | type=0x0003 Route Origin | transitive (IPv6-address-specific, RFC5701/7153) | **drop** | RFC5701 |
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701); 2-octet type field | type=0x0004 OSPFv3 Route Attributes (deprecated) | transitive (IPv6-address-specific, RFC5701/7153) | **drop** | RFC6565 |
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701); 2-octet type field | type=0x0005 IPv6-Address-Specific IFIT Tail Community | transitive (IPv6-address-specific, RFC5701/7153) | **drop** | draft-wang-idr-bgp-ifit-capabilities-02 |
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701); 2-octet type field | type=0x0006 Extension of Link Bandwidth Extended Community | transitive (IPv6-address-specific, RFC5701/7153) | **drop** | draft-li-idr-link-bandwidth-ext-01 |
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701); 2-octet type field | type=0x000b VRF Route Import | transitive (IPv6-address-specific, RFC5701/7153) | **drop** | RFC6515;RFC6514 |
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701); 2-octet type field | type=0x000c Flow-spec Redirect to IPv6 | transitive (IPv6-address-specific, RFC5701/7153) | **drop** | draft-ietf-idr-flowspec-redirect-ip-02 |
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701); 2-octet type field | type=0x000d Flow spec rt-redirect-ipv6 format | transitive (IPv6-address-specific, RFC5701/7153) | **drop** | RFC8956 |
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701); 2-octet type field | type=0x0010 Cisco VPN-Distinguisher | transitive (IPv6-address-specific, RFC5701/7153) | **drop** | Eric_Rosen |
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701); 2-octet type field | type=0x0011 UUID-based Route Target | transitive (IPv6-address-specific, RFC5701/7153) | **drop** | Dhananjaya_Rao |
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701); 2-octet type field | type=0x0012 Inter-Area P2MP Segmented Next-Hop | transitive (IPv6-address-specific, RFC5701/7153) | **drop** | RFC7524 |
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701); 2-octet type field | type=0x0014 VRF-Recursive-Next-Hop-Extended-Community | transitive (IPv6-address-specific, RFC5701/7153) | **drop** | Dhananjaya_Rao |
| 25 IPv6 Address Specific Extended Community | optional transitive (RFC5701); 2-octet type field | type=0x0015 RT-derived-EC | transitive (IPv6-address-specific, RFC5701/7153) | **drop** | draft-zzhang-idr-rt-derived-community-00 |
## UPDATE — Well-known and private-use communities
| attribute_type | attribute_trans | sub-type | sub-type_trans | send|drop | reference |
|----------------|-----------------|----------|----------------|---------|-----------|
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x04 QoS Marking | transitive | **drop** | IANA transitive/non-transitive types |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x05 CoS Capability | transitive | **drop** | IANA transitive/non-transitive types |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x07 FlowSpec Transitive Extended Communities | transitive | **drop** | IANA transitive/non-transitive types |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x08 Flow spec redirect/mirror to IP next-hop | transitive | **drop** | IANA transitive/non-transitive types |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x09 FlowSpec Redirect to indirection-id | transitive | **drop** | IANA transitive/non-transitive types |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x0c SRv6 MUP Extended Community | transitive | **drop** | IANA transitive/non-transitive types |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x44 QoS Marking (non-transitive) | non-transitive | **drop** | IANA transitive/non-transitive types |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x47 FlowSpec Non-Transitive Extended Communities | non-transitive | **drop** | IANA transitive/non-transitive types |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x04 QoS Marking | transitive | **drop** | Thomas_Martin_Knoll |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x05 CoS Capability | transitive | **drop** | Thomas_Martin_Knoll |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x07 FlowSpec Transitive Extended Communities | transitive | **drop** | draft-ietf-idr-flowspec-interfaceset-03 |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x08 Flow spec redirect/mirror to IP next-hop | transitive | **drop** | draft-simpson-idr-flowspec-redirect-01 |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x09 FlowSpec Redirect to indirection-id Extended Community | transitive | **drop** | draft-ietf-idr-flowspec-path-redirect-05 |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x0a Transport Class | transitive | **drop** | RFC9832 |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x0c SRv6 MUP Extended Community | transitive | **drop** | draft-mpmz-bess-mup-safi-00 |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x83-0x8f Reserved for Experimental Use | transitive | **drop** | RFC7153 |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x44 QoS Marking | non-transitive | **drop** | Thomas_Martin_Knoll |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x47 FlowSpec Non-Transitive Extended Communities | non-transitive | **drop** | draft-ietf-idr-flowspec-interfaceset-03 |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0x4a Non-Transitive Transport Class | non-transitive | **drop** | RFC9832 |
| 16 EXTENDED COMMUNITIES | optional transitive | type=0xc0-0xcf Reserved for Experimental Use | non-transitive | **drop** | RFC7153 |
## UPDATE — Attribute sub-TLVs and registries
| attribute_type | attribute_trans | sub-type | sub-type_trans | send|drop | reference |
|----------------|-----------------|----------|----------------|---------|-----------|
| BGP Prefix-SID | optional transitive (RFC8669) | bgp-prefix-sid-tlv-types:1 Label-Index | inherits attribute | **drop** | RFC8669 |
| BGP Prefix-SID | optional transitive (RFC8669) | bgp-prefix-sid-tlv-types:2 Deprecated | inherits attribute | **drop** | RFC8669 |
| BGP Prefix-SID | optional transitive (RFC8669) | bgp-prefix-sid-tlv-types:3 Originator SRGB | inherits attribute | **drop** | RFC8669 |
| BGP Prefix-SID | optional transitive (RFC8669) | bgp-prefix-sid-tlv-types:4 Deprecated | inherits attribute | **drop** | RFC9252 |
| BGP Prefix-SID | optional transitive (RFC8669) | bgp-prefix-sid-tlv-types:5 SRv6 L3 Service TLV | inherits attribute | **drop** | RFC9252 |
| BGP Prefix-SID | optional transitive (RFC8669) | bgp-prefix-sid-tlv-types:6 SRv6 L2 Service TLV | inherits attribute | **drop** | RFC9252 |
| BGP Prefix-SID | optional transitive (RFC8669) | bgp-prefix-sid-tlv-types:7 SRv6 Transport TLV | inherits attribute | **drop** | draft-sa-idr-bgp-srv6-mpls-transport-iw-02 |
| SFP attribute | optional transitive (RFC9015) | sfp-attribute-tlvs:1 Association TLV | inherits attribute | **drop** | RFC9015 |
| SFP attribute | optional transitive (RFC9015) | sfp-attribute-tlvs:2 Hop TLV | inherits attribute | **drop** | RFC9015 |
| SFP attribute | optional transitive (RFC9015) | sfp-attribute-tlvs:3 SFT TLV | inherits attribute | **drop** | RFC9015 |
| SFP attribute | optional transitive (RFC9015) | sfp-attribute-tlvs:4 MPLS Swapping/Stacking | inherits attribute | **drop** | RFC9015 |
| SFP attribute | optional transitive (RFC9015) | sfp-attribute-tlvs:5 SFP Traversal With MPLS | inherits attribute | **drop** | RFC9015 |
| BIER | optional transitive (RFC9793) | bgp-bier-tlv-sub-tlv-types:1 BIER TLV | inherits attribute | **drop** | |
| BIER | optional transitive (RFC9793) | bgp-bier-tlv-sub-tlv-types:2 MPLS Encapsulation sub-TLV | inherits attribute | **drop** | |
| BIER | optional transitive (RFC9793) | bgp-bier-tlv-sub-tlv-types:3 non-MPLS Encapsulation sub-TLV | inherits attribute | **drop** | |
| BIER | optional transitive (RFC9793) | bgp-bier-tlv-sub-tlv-types:4 BIER Nexthop sub-TLV | inherits attribute | **drop** | |
| BIER | optional transitive (RFC9793) | bgp-bier-tlv-sub-tlv-types:5 BIER PHP Request | inherits attribute | **drop** | |
## OPEN — Capabilities and optional parameters
| attribute_type | attribute_trans | sub-type | sub-type_trans | send|drop | reference |
|----------------|-----------------|----------|----------------|---------|-----------|
| Capabilities (optional parameter 2) | N/A (negotiation, not propagated in UPDATE) | code=1 Multiprotocol Extensions | session capability | **send** | IANA capability-codes |
| Capabilities (optional parameter 2) | N/A (negotiation, not propagated in UPDATE) | code=2 Route Refresh | session capability | **send** | IANA capability-codes |
| Capabilities (optional parameter 2) | N/A (negotiation, not propagated in UPDATE) | code=3 Outbound Route Filtering | session capability | **drop** | IANA capability-codes |
| Capabilities (optional parameter 2) | N/A (negotiation, not propagated in UPDATE) | code=5 Extended Next Hop Encoding | session capability | **send** | IANA capability-codes |
| Capabilities (optional parameter 2) | N/A (negotiation, not propagated in UPDATE) | code=6 BGP Extended Message | session capability | **send** | IANA capability-codes |
| Capabilities (optional parameter 2) | N/A (negotiation, not propagated in UPDATE) | code=7 BGPsec Capability | session capability | **drop** | IANA capability-codes |
| Capabilities (optional parameter 2) | N/A (negotiation, not propagated in UPDATE) | code=9 BGP Role | session capability | **send** | IANA capability-codes |
| Capabilities (optional parameter 2) | N/A (negotiation, not propagated in UPDATE) | code=64 Graceful Restart | session capability | **send** | IANA capability-codes |
| Capabilities (optional parameter 2) | N/A (negotiation, not propagated in UPDATE) | code=65 4-octet AS number | session capability | **send** | IANA capability-codes |
| Capabilities (optional parameter 2) | N/A (negotiation, not propagated in UPDATE) | code=69 ADD-PATH | session capability | **send** | IANA capability-codes |
| Capabilities (optional parameter 2) | N/A (negotiation, not propagated in UPDATE) | code=70 Enhanced Route Refresh | session capability | **send** | IANA capability-codes |
| Capabilities (optional parameter 2) | N/A (negotiation, not propagated in UPDATE) | code=71 Long-Lived Graceful Restart | session capability | **drop** | IANA capability-codes |
---
*Rows marked **drop** are conservative eBGP defaults; many operators also strip optional transitive communities at transit boundaries. Adjust per local AUP and service contracts.*
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