Subject: Re: Comments on <draft-ietf-isis-admin-tages-01.txt>

From: Alex Zinin <[email-masked]>
Date: Fri, 2 May 2003 16:11:23 -0400

Christian,

> This is probably the best solution.  The intention was (in my view)
> transparent to the SPT construction piece in that the only place where
> deletion or modification could/would occur is at LSP creation and on the
> area boundary (which in and of itself is an LSP re-creation process).  I am
> not sure that we intended to employ any real filtering in a standard
> implementation, although vendors do add knobs (or rope).

That's definitely reasonable.

> WRT to 64 bit tags, that was not my original intent - it came in later as a
> means to carry extended communties for carrier of carrier type applications.
> The semantics seemed such that stackin 32 bit tags for this purpose may
> introduce some ambiguity, so a separate sub-TLV was introduced.  I would
> think it would be easier to code in this fashion - Stefano?

That was also my reading of the discussion on the list I got from the
archives. My thinking would be that if the 64-bit TLV application is
really ext comm transportation, then it is not a tag that is used to
control prefix distribution within the domain any more, and this TLV
should be specified as "VPN foo:bar", instead of confusing
implementers and operators with two tags, which we clearly don't need.

Alex

---

From: "Martin, Christian" <[email-masked]>
Date: Fri, 2 May 2003 15:59:24 -0400

Alex,

>So maybe we should put in the text some words saying that 
>implementations should not use tags to change their routing 
>table calculation in a way that would affect interoperability 
>with preexisting implementations, or something like this.

Thanks for taking the time to get this clarified.

Chris

PS