[nsp] High CPU on 6400 NRP-1

[Clayton Zekelman]

Here it is - 30 users on PPPoE - 50% CPU.

C6400R Software (C6400R-G4P5-M), Version 12.2(15)T1,  RELEASE SOFTWARE (fc1)
TAC Support: http://www.cisco.com/tac
Compiled Thu 27-Mar-03 01:20 by ccai

No alignment data has been recorded.

Total Spurious Accesses 9159780, Recorded 2

  Address  Count  Traceback
       50  57906  0x60029DF8 0x6002CDD4
     1200  57906  0x60029E08 0x6002CDD4



At 12:01 PM 26/04/2004, Oliver Boehmer \(oboehmer\) wrote:
>Clayton,
>
>can u pls post "show align" from the NRP with the high CPU load?
>
>         oli
>
>----Original Message----
>From: cisco-nsp-bounces at puck.nether.net
>[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Clayton
>Zekelman Sent: Montag, 26. April 2004 15:54 To:
>cisco-nsp at puck.nether.net Subject: [nsp] High CPU on 6400 NRP-1
>
> > I'm having a strange problem on a 6400 NRP-1.
> >
> > With 20 users terminating with PPPoE, and CEF on, the router runs at
> > around 75% CPU, most of it interrupt.  If I turn off CEF, it drops to
> > around 1% CPU.
> >
> > I have another identical NRP that has around 450 users on it running
> > at 22%
> > CPU with CEF on.
> >
> > If I do a "show alignment" on the first unit with CEF on, the Spurious
> > Access counter climbs.  If I do it on the second unit, it does not.
> >
> > Both are running 12.2(15)T1.  The configurations are roughly the same
> > - the
> > only difference is the one with problems has a MTU of 1460 on the
> > Virtual
> > Template, and the one without has an MTU of 1454.  I'm wondering if
> > this is
> > causing the problem.  The users have been bounced a whole bunch
> > lately, so
> > I'm not inclined to change it right now.
> >
> > Interesting to note that I had a 7206 with an NPE-200 exhibiting the
> > same
> > strange behavior, but when I swapped out to an NPE-225, it went away
> > - CEF
> > worked fine.  From what I remember, the NRP-1 and the NPE-200 share
> > some
> > architectural similarities.
> >
> > I also have a couple of NRP-1's terminating around 900 users each
> > through
> > L2TP running around 50% interrupt, with the Spurious Access counter
> > climbing.  Doesn't seem to be huge issue right now.
> >
> > I'm wondering if the MTU issue and fragmentation are related to the
> > high
> > interrupt load.  There is a bug ID (CSCeb87509) that talks about
> > something
> > similar, but we're not running SSG, and its listed as
> > un-reproduceable.
> >
> > I can flip CEF on, and watch the router load go up, then switch it
> > off, and
> > it goes right back down again.  I'm afraid that once I have more
> > users on
> > the unit, I'll need CEF to be able to handle the load.
> >
> > In all cases, I have dot1q trunking on the routers - this was listed
> > in the
> > Bug ID as a condition.
> >
> > Suggestions?  Insight?  Could it be fragging related to the MTU?
> >
> >
> >
> > ---
> > Clayton Zekelman
> > Managed Network Systems Inc. (MNSi)
> > 344-300 Tecumseh Rd. E.
> > Windsor, Ontario
> > N8X 5E8
> >
> > tel. 519-985-8410
> > fax. 519-258-3009
> >
> > _______________________________________________
> > cisco-nsp mailing list  cisco-nsp at puck.nether.net
> > https://puck.nether.net/mailman/listinfo/cisco-nsp
> > archive at http://puck.nether.net/pipermail/cisco-nsp/

---
Clayton Zekelman
Managed Network Systems Inc. (MNSi)
344-300 Tecumseh Rd. E.
Windsor, Ontario
N8X 5E8

tel. 519-985-8410
fax. 519-258-3009