Subject: [trill] Alissa Cooper's No Objection on draft-ietf-trill-directory-assist-mechanisms-11: (with COMMENT)

From: "Alissa Cooper" <[email-masked]>
Date: Wed, 18 Jan 2017 07:58:56 -0800

Alissa Cooper has entered the following ballot position for
draft-ietf-trill-directory-assist-mechanisms-11: No Objection

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COMMENT:
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Since this document implies the creation of centralized databases of
addressing information, I think it would help to call out in Section 6
the need to secure the directory contents themselves, not just against
abuses of the push or pull services but in general against unauthorized
access.

Also, I recall in prior evaluations of TRILL documents some discussion
about how TRILL deals with ephemeral MAC addresses and my recollection is
that they are likely prohibited by policy on TRILL networks. But if there
is some interaction between ephemeral MAC addresses and the services
described in this document that would be good for implementors to be
aware of, those are probably worth mentioning.

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From: Donald Eastlake <[email-masked]>
Date: Wed, 18 Jan 2017 14:02:12 -0500

Hi Alissa,

> introductory paragraph, however.)

Yes, although such centralized databases are quite common currently in
terms of data center management and orchestration system databases.

> abuses of the push or pull services but in general against unauthorized

OK.

I'm not sure the need to secure directories resident on TRILL switches
is that much different from the need to secure the routing function
and routing data of TRILL switches. But the draft also supports Pull
Directories hosted on end stations and I think something should be
said about end station security in connection with the end station
hosting a directory.

> that they are likely prohibited by policy on TRILL networks. But if there

The payload of a TRILL Data packet looks like an Ethernet frame. TRILL
delivers it to end station(s) based on the destination MAC address
and, by default, learns about MAC reachability by observing the source
MAC address. So, while I would not say ephemeral or frequently
changing MAC addresses are prohibited by "policy", they would reduce
the efficiency of a TRILL campus by frequently obsoleting learned MAC
reachability information.

> aware of, those are probably worth mentioning.

Directories need not be complete. If, for example, there were servers
with fixed MACs and clients with mostly ephemeral MACs, I think it
would still be reasonable to have the reachability (edge attachment
point) information for the fixed MACs in a directory. Something about
this could be added to the draft.

Thanks,
Donald
===============================
 Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
 155 Beaver Street, Milford, MA 01757 USA
 [email-masked]

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From: Alissa Cooper <[email-masked]>
Date: Thu, 19 Jan 2017 09:21:21 -0500

> On Jan 18, 2017, at 2:02 PM, Donald Eastlake <[email-masked]> wrote:
> 
> Hi Alissa,
> 

Sounds good.

> this could be added to the draft.

I think that would be helpful.

Thanks,
Alissa