Neeraj,

On Thu, Jul 24, 2025 at 02:24:33PM +0000, Neeraj Malhotra (nmalhotr) wrote:
> Thanks for the note. Could you please check if the text added in section 7.7 
> is sufficient? This adds a reference to evpn-ipvpn-interworking draft that 
> already has a section stating that attributes of type EVPN should NOT be 
> preserved from EVPN to non-EVPN networks. There is also text added to explain 
> why it is not beneficial to carry EVPN LBW into non-EVPN networks (in line 
> with the point you have below).
> 
> Wanted to refrain from this draft defining interworking behavior and instead 
> leave that for the interworking draft to define. Would it be clearer instead 
> if this draft also explicitly states that the attribute should be dropped?

Avoiding redundant procedures is great.

The detail as you mention is appropriately captured as you say:
"This extended community is defined of type 0x06 (EVPN Extended Community
Sub-Types)"

and in ipvpn-inter...

5.2.4:
: As discussed in point 1, Communities, Extended Communities, Large
: Communities and Wide Communities SHOULD be preserved from the originating
: ISF route by the gateway PE. Exceptions of Extended Communities that SHOULD
: NOT be propagated are:
: 
: BGP Encapsulation extended communities [RFC9012].
: 
: Route Target extended communities. Route Targets are always initialized when
: readvertising an ISF route into a different domain, i.e., they are not
: propagated. The initialized Route Target in the re-advertised ISF route may
: or may not have the same value as the Route Target of the originating ISF
: route.
: 
: All the extended communities of type EVPN.
  ^^^^^^^^^^

So, my concern is addressed.  Thanks for pointing out the error of my casual
reading.

-- Jeff

> 
> Thanks,
> Neeraj
> 
> From: Jeffrey Haas <[email protected]>
> Date: Thursday, July 24, 2025 at 6:31 AM
> To: [email protected] 
> <[email protected]>, [email protected] <[email protected]>
> Subject: EVPN Link BW community cleanup
> One thing I noted while browsing through the draft again after today's bess
> presentation was a lack of text regarding "cleanup" of the EVPN LBW
> community. (Although perhaps I'm browsing too shallowly.)
> 
> The community is defined as transitive, and procedures exist wherein EVPN
> routes that may carry this community may be carried back and forth in
> an Internet context. This means there exists the possibility that such EVPN
> LBW communities may pass between networks where their context is different.
> That is, network 1 shouldn't use network 2's bandwidth.
> 
> Community scrubbing is thus recommended.
> 
> Please consider reviewing the following document's section 7.5 for some
> general wisdom and consider what text should be added to your draft that
> might be appropriate for this situation.
> 
> https://datatracker.ietf.org/doc/draft-ietf-grow-routing-ops-sec-inform/
> 
> -- Jeff

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