[j-nsp] BGP Prefix-Limit On A Session

[Pedro Roque Marques]

Kashif.Khawaja at Broadwing.com writes:


Kashif,

> Hi All,

> Just wanted to confirm something. "Injected" in the text
> below refers to prefixes accepted into the BGP table?

Yes.

> Prefixes that passed the import policies?

And also prefixes that did not pass import policies.

The default behaviour for processing a received BGP path ('keep
none/all' change this):

1) perform a set of basic checks (as-path loop detection, etc). If the
test fails discard the route... doesn't get installed in the routing
table, etc.

2) perform import policy. If the policy fails the route still gets
stored in the routing table but w/ a preference that makes it
unusable. This is done so that when import policy is changed, the
router can locally reevaluate policy for routes that it has rejected.

This entries that do not pass import policy do consume resources and
such are counted against prefix-limit parameters.

o "keep all" instructs the router to keep paths that fail test  1)
o "keep none"   " "  " "     "    "  reject paths that fail test 2)

But i would advise against fiddling w/ those... unless you really
must.

  Pedro.