Hi Sasha,

Your understanding is correct. With respect to your two minor issues below, we 
will take care of them in the next rev along with enhancement to the proxy 
procedure to avoid gleaning of IP traffic. The draft already mentions the 
latter one.

Cheers,
Ali

From: Alexander Vainshtein <alexander.vainsht...@rbbn.com>
Date: Monday, November 6, 2023 at 11:17 PM
To: Ali Sajassi (sajassi) <saja...@cisco.com>, Neeraj Malhotra 
<neeraj.i...@gmail.com>
Cc: draft-sajassi-bess-evpn-l3-optimized-...@ietf.org 
<draft-sajassi-bess-evpn-l3-optimized-...@ietf.org>, bess@ietf.org 
<bess@ietf.org>, Nitsan Dolev <nitsan.do...@rbbn.com>, Ali Sajassi (sajassi) 
<sajassi=40cisco....@dmarc.ietf.org>
Subject: RE: [bess] A question about draft-sajassi-bess-evpn-l3-optimized-irb
Ali, Neeraj and all,
Lots of thanks for prompt responses and clarifications.

My reading of your responses looks as following:

  1.  An optimized IRB is a Symmetric EVPN IRB:

     *   It advertises an RT-2 with the Label2 field present and RTs of both 
MAC-VRF and IP-VRF attached for each IP-->MAC pair it locally learns
     *   The Label2 field carries the label that identifies the IP-VRF that 
contains the EVPN IRB in question

  1.  Traditional Proxy ARP for the subnet of the of this IRB (making it 
respond with its own MAC address to ARP requests for any ARP requests to 
addresses from its subnet is enabled
  2.  An dedicated Extended Community is attached to RT-2 mentioned above and 
indicating that this route MUST be installed (as a host route) in IB and FIB of 
IP-VRF with matching Import RT and in the “RIB” but not in the FDB of the 
MAC-VRF with matching Import RT.

If this understanding is correct, I see a minor issue with this draft (the 
relevant text is highlighted for clarity):
Section 2.1.1 of the 
draft<https://datatracker.ietf.org/doc/html/draft-sajassi-bess-evpn-l3-optimized-irb-00#section-2.1.1>
 says that the PE operating in the optimized IRB mode “advertises a MAC/IP 
Advertisement route (aka route-type 2) along with a flag (via BGP extended 
community) to indicate this mode of operation so that the receiving PE adds the 
received MAC address to the L2RIB table but not the L2FIB”.  However:

  1.  AFAIK, no such flag has, so far, been defined in any Extended Community 
used in EVPN
  2.  Section 6 “IANA considerations” of the draft says, “This document 
requests no actions from IANA”.

Should be trivial to fix in the next revision of the draft, I think.

My 2c,
Sasha

From: Ali Sajassi (sajassi) <saja...@cisco.com>
Sent: Tuesday, November 7, 2023 3:41 AM
To: Neeraj Malhotra <neeraj.i...@gmail.com>; Ali Sajassi (sajassi) 
<sajassi=40cisco....@dmarc.ietf.org>
Cc: Alexander Vainshtein <alexander.vainsht...@rbbn.com>; 
draft-sajassi-bess-evpn-l3-optimized-...@ietf.org; bess@ietf.org; Nitsan Dolev 
<nitsan.do...@rbbn.com>
Subject: [EXTERNAL] Re: [bess] A question about 
draft-sajassi-bess-evpn-l3-optimized-irb

Hi Neeraj,

Exactly! And I mentioned this during my presentation at BESS. It Is also 
explicitly described in section 2.1.1 of the draft:


“  Since there is no L2 forwarding, there is no need
   for populating L2FIB; however, L2RIB needs to be populated for host
   mobility procedures because host mobility in EVPN is based on MAC
   mobility which is tracked in L2RIB.”

Cheers,
Ali
From: Neeraj Malhotra <neeraj.i...@gmail.com<mailto:neeraj.i...@gmail.com>>
Date: Monday, November 6, 2023 at 4:13 PM
To: Ali Sajassi (sajassi) 
<sajassi=40cisco....@dmarc.ietf.org<mailto:sajassi=40cisco....@dmarc.ietf.org>>
Cc: Alexander Vainshtein 
<alexander.vainsht...@rbbn.com<mailto:alexander.vainsht...@rbbn.com>>, 
draft-sajassi-bess-evpn-l3-optimized-...@ietf.org<mailto:draft-sajassi-bess-evpn-l3-optimized-...@ietf.org>
 
<draft-sajassi-bess-evpn-l3-optimized-...@ietf.org<mailto:draft-sajassi-bess-evpn-l3-optimized-...@ietf.org>>,
 bess@ietf.org<mailto:bess@ietf.org> <bess@ietf.org<mailto:bess@ietf.org>>, 
Nitsan Dolev <nitsan.do...@rbbn.com<mailto:nitsan.do...@rbbn.com>>
Subject: Re: [bess] A question about draft-sajassi-bess-evpn-l3-optimized-irb

Hi Ali, Sasha,

minor comment in case it wasn't already clear - each PE still learns all MACs 
in the control plane (for mobility procedures to work) but only locally 
connected MACs are installed in the forwarding plane. Hence the optimization. 
Ali, please confirm.

Thanks,
Neeraj

On Mon, Nov 6, 2023 at 11:37 AM Ali Sajassi (sajassi) 
<sajassi=40cisco....@dmarc.ietf.org<mailto:40cisco....@dmarc.ietf.org>> wrote:
Hi Sasha,

Each PE only learns local MAC addresses and NOT remote ones. So, lets says you 
have a subnet that is stretched across 10 PEs and each PE has 100 locally 
connected hosts. So, the total number of MAC addresses for the subnet is 1000 
(10X100) but each PE ONLY learns 100 MAC addresses. This is in contrast with 
the traditional EVPN-IRB where each PE learns all 1000 MAC addresses.

Cheers,
Ali

From: BESS <bess-boun...@ietf.org<mailto:bess-boun...@ietf.org>> on behalf of 
Alexander Vainshtein 
<alexander.vainsht...@rbbn.com<mailto:alexander.vainsht...@rbbn.com>>
Date: Monday, November 6, 2023 at 5:31 AM
To: 
draft-sajassi-bess-evpn-l3-optimized-...@ietf.org<mailto:draft-sajassi-bess-evpn-l3-optimized-...@ietf.org>
 
<draft-sajassi-bess-evpn-l3-optimized-...@ietf.org<mailto:draft-sajassi-bess-evpn-l3-optimized-...@ietf.org>>
Cc: bess@ietf.org<mailto:bess@ietf.org> <bess@ietf.org<mailto:bess@ietf.org>>, 
Nitsan Dolev <nitsan.do...@rbbn.com<mailto:nitsan.do...@rbbn.com>>
Subject: [bess] A question about draft-sajassi-bess-evpn-l3-optimized-irb
Hi,
This the question I have tried to ask during the meeting.

The Introduction to draft in 
question<https://datatracker.ietf.org/doc/html/draft-sajassi-bess-evpn-l3-optimized-irb-00#section-1>
  claims “improving MAC scalability of customer bridges and PE devices 
significantly”.
The first of these claims is easy to understand: each specific CE switch has to 
learn just one MAC address (that of the optimized IRB) in addition to MAC 
addresses of its locally attached hosts.

But I have doubts about the second of these claims: to the best of my 
understanding, each PE attached to the subnet in question will learn MAC 
addresses of all attached hosts in the subnet.

What, if anything, did I miss?

Regards, and lots of thanks in advance,
Sasha



Disclaimer

This e-mail together with any attachments may contain information of Ribbon 
Communications Inc. and its Affiliates that is confidential and/or proprietary 
for the sole use of the intended recipient. Any review, disclosure, reliance or 
distribution by others or forwarding without express permission is strictly 
prohibited. If you are not the intended recipient, please notify the sender 
immediately and then delete all copies, including any attachments.
_______________________________________________
BESS mailing list
BESS@ietf.org<mailto:BESS@ietf.org>
https://www.ietf.org/mailman/listinfo/bess
_______________________________________________
BESS mailing list
BESS@ietf.org
https://www.ietf.org/mailman/listinfo/bess

Reply via email to