Subject: [secdir] Secdir telechat review of draft-ietf-trill-multilevel-single-nickname-15

From: Samuel Weiler via Datatracker <[email-masked]>
Date: Tue, 05 Oct 2021 13:07:55 -0700

Reviewer: Samuel Weiler
Review result: Not Ready

I'm not satisfied with the weak anti-spoofing protections of TRILL, but I don't
see this making things worse.

I have what I hope is a naive question: since this proposes to label level 1
areas by the set of RBs that connect them to the level 2, expanding on Section
6 (One Border RBridge Connects Multiple Areas), what happens when the set of
RBs connecting to multiple areas is the same, such that all of those areas
would then get the same name, under this scheme?   (I'm hoping this works, and
I'm just not sorting out the details, but I'm making sure...)

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From: Donald Eastlake <[email-masked]>
Date: Tue, 5 Oct 2021 21:33:34 -0400

Hi,

See below.

> see this making things worse.

Can you be more specific? Are you talking about spoofing routing control
messages or spoofing data or what?

> I'm just not sorting out the details, but I'm making sure...)

In the situation you hypothesize, there are three cases generally covered
by Section 6 of the draft:

   - There is no reason to treat outbound traffic to L2 from any of the L1
   areas you hypothesize differently from any other, so there is no problem in
   this case.
   - On inbound traffic from L2, the MAC and data label have to be looked
   up to determine the egress RBridge and output port and the output port
   determines the actual L1 area.
   - On traffic between L1 areas on an border RBridge, that border RBridge
   will see itself as the egress nickname in the TRILL packet it receives and
   do the lookup as in the immediately previous case.

I am working on an update to resolve various IESG COMMENTs which should be
posted shortly.

Thanks,
Donald
===============================
 Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
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