Early Review of draft-ietf-trill-irb-09
review-ietf-trill-irb-09-rtgdir-early-white-2016-01-15-00

Y'all --

I have been selected as the Routing Directorate reviewer for this draft. The
Routing Directorate seeks to review all routing or routing-related drafts as
they pass through IETF last call and IESG review, and sometimes on special
request. The purpose of the review is to provide assistance to the Routing ADs.
For more information about the Routing Directorate, please see ​

http://trac.tools.ietf.org/area/rtg/trac/wiki/RtgDir

Although these comments are primarily for the use of the Routing ADs, it would
be helpful if you could consider them along with any other IETF Last Call
comments that you receive, and strive to resolve them through discussion or by
updating the draft.

Document: draft-ietf-trill-irb-09.txt
Reviewer: Russ White
Review Date: 28 December 2015
Intended Status: Standard Track

I have some minor concerns about this document that I think should be resolved
before publication.

First, in 5.2:

When a routing instance is created on an edge RBridge, the tenant ID, tenant
Label (VLAN or FGL), tenant gateway MAC, and their correspondence should be set
and globally advertised (see Section 7.1).

When an ingress RBridge performs inter-subnet traffic TRILL encapsulation, the
ingress RBridge uses the Label advertised by the egress RBridge as the inner
VLAN or FGL and uses the tenant gateway    MAC advertised by the egress RBridge
as the Inner.MacDA. The egress Bridge relies on this tenant Data Label to find
the local VRF instance for the IP forwarding process when receiving
inter-subnet traffic from the TRILL campus. (The role of tenant Label is akin
to an MPLS VPN Label in an MPLS IP/MPLS VPN network.) Tenant Data Labels are
independently allocated on each edge RBridge for each routing domain.

There seems to be some confusion between the concepts of a tenant label and a
tenant data label. Is the tenant label globally set and advertised, or is it
locally set on a per edge RBridge basis? Is it the set of tenant id + tenant
lable that is meant to be unique, or -- ?? This seems like it could use some
clarification.

Second, it seems that the way this should work would be with host routes at
layer 3. I'm not certain how a subnet route would really work given the ability
of the operator to split a subnet across multiple flooding domains under
multiple ToR devices. Is this correct? There doesn't seem to be any mention in
the document.

The formatting of the document looks fine. There do not appear to be any
downrefs. The security considerations section appears to be useful, and to
cover the issues I could think of when reading through the doc.

:-)

Russ