Hello Authors of draft-ietf-bess-rfc7432bis-04
I have a query regarding the following text in the section
"https://datatracker.ietf.org/doc/html/draft-ietf-bess-rfc7432bis#section-1"5:
"If two (or more) PEs advertise the same MAC
address with the same sequence number but different Ethernet segment
identifiers, a PE that receives these routes selects the route
advertised by the PE with the lowest IP address as the best route."
How do we deal with scenario's like DCI (inter-fabric scenarios),
where-in the next-hop can change values in the control plane intermediate
hop(s),
Let's say, via route-maps, a fabric border router sets the next-hop to self
and republishes
to local peers, hence the originating routers IP address is lost. We should
call this out explicitly.
Consider the following diagram, with Fabric-1 consisting of Bgp1 and
Border_bgp1 peers. Same semantics for Fabric-2.
Border-Bgp1 and Border_Bgp2 can very well change the next-hop values before the
routes reaches the other end (bgp1 or bgp2)
Host_MAC----[Bgp1]-----(ibgp)-------[Border_Bgp1]=====(ebgp)=====[Boder_bgp2]--------(ibgp)----------[Bgp2]----Host_MAC
Bgp1 originates the Host_MAC route with local ip-address Next-hop-IP1.
Border_Bgp1 and Boder_Bgp2 peers may alter the Next-hop IP to self (or anything
else).
Bgp2 may receive it with Next-Hop-IP-Border. Bgp2 also originates the same
Host_MAC route with Next-hop-IP2 as local-ip-address.
Let's say the following configuration prevails:
If (Next-hop-IP1 > Next-Hop-IP-Border) AND
(Next-Hop-IP2 > Next-Hop-IP-Border) AND
(Next-Hop-IP2 > Next-Hop-IP1)
Then both Bgp1 and Bgp2 end up selecting the remote routes as best, ending up
in inconsistent states.
This needs to be called out or a mechanism to be added to ebb it's impact.
I might be missing some literature in other drafts which are already solving
this problem. If yes, in please help with the pointers.
Thanks
Saumya.
-----Original Message-----
From: BESS [mailto:[email protected]] On Behalf Of [email protected]
Sent: Tuesday, March 8, 2022 12:07 AM
To: [email protected]
Cc: [email protected]
Subject: [bess] I-D Action: draft-ietf-bess-rfc7432bis-04.txt
A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the BGP Enabled ServiceS WG of the IETF.
Title : BGP MPLS-Based Ethernet VPN
Authors : Ali Sajassi
Luc Andre Burdet
John Drake
Jorge Rabadan
Filename : draft-ietf-bess-rfc7432bis-04.txt
Pages : 70
Date : 2022-03-07
Abstract:
This document describes procedures for BGP MPLS-based Ethernet VPNs
(EVPN). The procedures described here meet the requirements
specified in RFC 7209 -- "Requirements for Ethernet VPN (EVPN)".
Note to Readers
_RFC EDITOR: please remove this section before publication_
The complete and detailed set of all changes between this version and
RFC7432 may be found as an Annotated Diff (rfcdiff) here
(https://tools.ietf.org/rfcdiff?url1=https://www.rfc-
editor.org/rfc/rfc7432.txt&url2=https://www.ietf.org/archive/id/
draft-ietf-bess-rfc7432bis-04.txt).
The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-ietf-bess-rfc7432bis/
There is also an htmlized version available at:
https://datatracker.ietf.org/doc/html/draft-ietf-bess-rfc7432bis-04
A diff from the previous version is available at:
https://www.ietf.org/rfcdiff?url2=draft-ietf-bess-rfc7432bis-04
Internet-Drafts are also available by rsync at rsync.ietf.org::internet-drafts
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