[Idr] draft-uttaro-idr-bgp-persistence

[Robert Raszuk <[e-mail]>]

Hi,

Assume LLGR has been negotiated and routes have been exchanged with LLGR
community. The retention timer is looong.

While I am happy to see that suggestions to follow GR procedures have been
used the draft is pretty silent on one very important aspect - clearing
persistent routes. GR procedures which rely on using GR time for it do not
apply.

Imagine I want to bring such session down and I do want to remove all
routes including those marked as LLGR. How do I do that ?

>From current draft the only way seems to be to reestablish a session with
LLGR capability and readvertise subject routes with NO-LLGR community
hoping it will clear the former routes. But even here we are at the mercy
of local policy as per section 3.2 & 3.3

In any case that is pretty awkward method.

Then we just had a little thread regarding max prefix in GROW WG. New draft
there actually relies on BGP NOTIFICATION MSG with CEASE error code to
remove all routes making on purpose crossing a max prefix limit a drastic
event (of course unless warning only is set).

Bottom line BGP here is used again as configuration tool not as dynamic
routing protocol. I do not think this type of use of BGP which should be
endorsed.

If this proposal moves fwd it should clearly spell how not only to retain
the LLGR eligible prefixes but also how to cleanly remove them when needed
- way before they expire.

Kind regards,
R.