Subject: EVPN: IP mappings after MAC move

From: Jakob Heitz <[email-masked]>
Date: Sat, 24 Aug 2013 01:05:06 +0000

At the meeting, there was confusion about what to do about MAC-IP mapping advertisements after a MAC move.
To me section 16 is clear:

   In order to allow all of the PEs in the EVPN instance to correctly
   determine the current location of the MAC address, all advertisements
   of it being reachable via the previous Ethernet segment MUST be
   withdrawn by the PEs, for the previous Ethernet segment, that had
   advertised it.

Perhaps, you could add a sentence:

   This includes all MAC advertisement routes of the affected MAC address
   that contain an IP address.

The IP-MAC mapping advertisement contains a label and a nexthop, so
it is really also a MAC advertisement at the same time. If that were
to stay around, it would confuse the real location.
The PE at the new location can snoop ARP messages and issue its own
MAC-IP mapping.

Alternatively, IP-MAC mappings could be made into separate messages
decoupled from the MAC location advertisement.

Thanks,
Jakob.

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From: Linda Dunbar <[email-masked]>
Date: Sat, 24 Aug 2013 16:06:47 +0000

I agree with Jakob's suggestion in the last sentence:

IP-MAC mappings could be made into separate messages decoupled from the MAC location advertisement.

When a host moves from one PE to another, the IP-MAC mapping doesn't change. The only change is the MAC attachment to the PE.

Linda

From: [email-masked] [mailto:[email-masked]] On Behalf Of Jakob Heitz
Sent: Friday, August 23, 2013 8:05 PM
To: [email-masked]; Ali Sajassi (sajassi)
Subject: EVPN: IP mappings after MAC move

Thanks,
Jakob.