Derrick, Possible a missing next-hop attribute can be the case?
From [0]:
attribute EBGP IBGP
ORIGIN mandatory mandatory
AS_PATH mandatory mandatory
NEXT_HOP mandatory mandatory
ORIGIN and AS_PATH is attached as attributes to the BGP Update Message.
No NEXT_HOP, thou.
Christoffer [0]: https://tools.ietf.org/html/rfc4271#section-5 (p. 25) On 11/07/2019 13:41, Derrick Lim wrote:
Hello everyone, I’m having an issue with FRR running on Cumulus (4.0+cl3u10), which is peering BGP to BIRD (2.0.2, also tried 1.6.3). When certain routes from FRR are advertised to BIRD (I configured them through vrf leaking on FRR, but not sure if that matters, or its just something with the routes), BIRD terminates the BGP session with an `Optional attribute error` (on BIRD 2.0.2, different error on 1.6.3) when receiving the BGP UPDATE message. I’m not sure if this an FRR or BIRD issue, so I'm hoping someone here could take a look if the UPDATE message from FRR could possibly be malformed, or is BIRD handling this in an odd way. I've attached the tcpdump as well as error logs from BIRD, along with the bird.conf, as well a portion of the FRR config. 100.91.38.1 is the host running BIRD. 100.91.38.61 is the host running FRR. Regards, Derrick
Frame 40: 130 bytes on wire (1040 bits), 130 bytes captured (1040 bits)
Linux cooked capture
802.1Q Virtual LAN, PRI: 0, DEI: 0, ID: 1000
Internet Protocol Version 4, Src: 100.91.38.61, Dst: 100.91.38.1
Transmission Control Protocol, Src Port: 179, Dst Port: 54139, Seq: 112, Ack:
100, Len: 58
Border Gateway Protocol - UPDATE Message
Marker: ffffffffffffffffffffffffffffffff
Length: 58
Type: UPDATE Message (2)
Withdrawn Routes Length: 0
Total Path Attribute Length: 34
Path attributes
Path Attribute - ORIGIN: IGP
Flags: 0x40, Transitive, Well-known, Complete
0... .... = Optional: Not set
.1.. .... = Transitive: Set
..0. .... = Partial: Not set
...0 .... = Extended-Length: Not set
.... 0000 = Unused: 0x0
Type Code: ORIGIN (1)
Length: 1
Origin: IGP (0)
Path Attribute - AS_PATH: 4272357393 4272357377 4272357378 4272357376
4259905537 54058
Flags: 0x50, Transitive, Extended-Length, Well-known, Complete
0... .... = Optional: Not set
.1.. .... = Transitive: Set
..0. .... = Partial: Not set
...1 .... = Extended-Length: Set
.... 0000 = Unused: 0x0
Type Code: AS_PATH (2)
Length: 26
AS Path segment: 4272357393 4272357377 4272357378 4272357376
4259905537 54058
Segment type: AS_SEQUENCE (2)
Segment length (number of ASN): 6
AS4: 4272357393
AS4: 4272357377
AS4: 4272357378
AS4: 4272357376
AS4: 4259905537
AS4: 54058
Network Layer Reachability Information (NLRI)
0.0.0.0/0
NLRI prefix length: 0
NLRI prefix: 0.0.0.0
signature.asc
Description: OpenPGP digital signature
