[c-nsp] Idle sessions on 12.2(33)SR cause high CPU

[Byrd, William]

Yes, SRC3 has a known bug related to memory leaks on idle/active BGP peers:

CSCsy58115 Bug Details Continuous BGP mem increase with non established
neighbors

Symptom:

In a router running BGP the BGP Router process may hold increased amounts of
memory over time without freeing any memory. This may also be seen from the
output of "show proc mem sort" and in the output of "show ip bgp sum" or
"show ip bgp vpnv4 all sum" and looking at the number of BGP attributes
which may be increasing over time in relation to the BGP prefixes and paths
which may remain roughly the same.

Conditions:

Some BGP neighbors are not in established state and exchanging prefixes. The
issue is observed on all platforms running 12.2(31)SB14 12.2(33)SB1b
12.2(33)SB2 12.2(33.05.14)SRB 12.2(33.02.09)SRC 12.2(33)SRC3 12.4(20)T2
12.4(22)T1
12.2(33)SXI or later releases.

Workaround:

Remove the configuration lines related to the inactive neighbors (neighbors
in Idle or Active states).

On Fri, Dec 11, 2009 at 6:52 AM, Daniel Holme <Daniel.Holme at kcom.com> wrote:

> Yes I've experienced this on a 7600 running 12.2(33)SRC3.
>
> I have experienced it a number of times too, one of which was the XP
> issue you mention.
>
> You don't want too many people configuring passive sessions as having
> that on both ends is equally as bad as shutting down the session.
>
> --Dan
>
> > -----Original Message-----
> > From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-
> > bounces at puck.nether.net] On Behalf Of Zoe O'Connell
> > Sent: 11 December 2009 10:20
> > To: cisco-nsp at puck.nether.net
> > Subject: [c-nsp] Idle sessions on 12.2(33)SR cause high CPU
> >
> > Hi,
> >
> > As a result of issues at an exchange point over the last few days, a
> > number of us (ISPs) have noticed an issue with BGP sessions sitting in
> > the "Idle" state, because the other end is shut down.
> >
> > Basically, it appears that on Sup720s at least, once you reach a
> > critical number of sessions in Idle (More than 5, less than 20) the
> CPU
> > usage increases to 30%, all down to the BGP Router process. 30ish
> > sessions down and it's up to 50% - we've had ours up to 70% as a
> result
> > of this, although I don't know how many sessions were down at that
> > point. This behaviour has been confirmed on 12.2(33)SRC4 and
> > 12.2(33)SRD2, with other possible reports on SXF, SRC3, SRC5 and also
> on
> > CRS-1s. Has anyone seen this before and know if it's a known issue
> with
> > a BugID associated?
> >
> > A workaround is to apply "neigh x.x.x.x transport connection passive"
> > but this clearly isn't optimal.
> > _______________________________________________
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