Subject: [Idr] Unspecified handling of multiple ADD-PATH capabilities

From: Ondrej Zajicek <[email-masked]>
Date: Fri, 15 Jul 2016 11:29:18 +0200

Hi

draft-ietf-idr-add-paths-15 does not specify how multiple ADD-PATH
capability instances received in one OPEN message should be handled.

There are at least three incompatible possibilities:

1) Ignore all but first/last (like RFC 4724).

2) Merge on per-AF basis, use first/last per AF.

3) Merge on per-(AF+direction) basis

Note that RFC 5492 requires handling of multiple instances to be specified:

   BGP speakers MAY include more than one instance of a capability (as
   identified by the Capability Code) with non-zero Capability Length
   field, but with different Capability Value and either the same or
   different Capability Length.  Processing of these capability
   instances is specific to the Capability Code and MUST be described in
   the document introducing the new capability.

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: [email-masked])
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."