[c-nsp] c6k msfc - hsrp flapping

lee.e.rian at census.gov lee.e.rian at census.gov
Fri May 19 05:17:31 EDT 2006 

Hi Yuri,

"Yuri Lukin" <lists at swaggi.com> wrote on 05/18/2006 04:11:10 PM:

> > The closest match is the section on HSRP Intermittent State Changes on
> > Multicast Stub Network.  But I'm pretty sure that isn't that problem
> > because the non-dr router is msfc1.  Msfc2 is the router having all the
> > problems with hsrp flapping.
>
> Think about it from another perspective: what if too much multicast
traffic
> hitting your DR (msfc2) is causing HSRP issues?

The assumption I've been making is that enough multicast traffic hitting
the msfc to cause hsrp and eigrp to flap would also cause very high cpu
busy and/or lots of input queue drops.  Maybe that's a bad assumption, but
that's why I think the traffic is being dropped before it gets to the msfc.
But I don't know what commands to run to prove or disprove that theory.

> Are these switches hybrid or native?

Hybrid  Sup1a/msfc
They were scheduled to be upgraded in the near future but they just jumped
to the head of the line :-)
I think we're just going to leave multicast turned off to this site until
they're upgraded.

> How are they interconnected?

L3 point-to-point links between the routers.

> Can you check the various counters to see which interfaces are
> showing excessive multicast traffic?

None of the multicast counts look excessive to me
  (counters haven't been cleared & uptime is 2 days, 16 hours)
I hadn't thought about it until now, but unless hsrp keepalives aren't
counted the multicast counts are impossibly low.

Lots of broadcasts, but we have IPX and Decnet at this site.

msfc2#sh int | inc mult
     Received 1258545 broadcasts (158 IP multicast)
     Received 901605 broadcasts (146 IP multicast)
     Received 615971 broadcasts (24 IP multicast)
     Received 677219 broadcasts (13 IP multicast)
     Received 595778 broadcasts (142 IP multicast)
     Received 580679 broadcasts (24976 IP multicast)
     Received 398487 broadcasts (9 IP multicast)
     Received 994727 broadcasts (23 IP multicast)
     Received 522485 broadcasts (50 IP multicast)
     Received 539081 broadcasts (12 IP multicast)
     Received 603623 broadcasts (9 IP multicast)
     Received 531783 broadcasts (6 IP multicast)
     Received 310361 broadcasts (4 IP multicast)
     Received 513320 broadcasts (7 IP multicast)
     Received 587772 broadcasts (20 IP multicast)
     Received 537649 broadcasts (9 IP multicast)
     Received 529475 broadcasts (65615 IP multicast)
     Received 297437 broadcasts (0 IP multicast)
     Received 547120 broadcasts (17532 IP multicast)
     Received 806704 broadcasts (85 IP multicast)
     Received 1621485 broadcasts (31 IP multicast)
     Received 1550681 broadcasts (0 IP multicast)
     Received 647764 broadcasts (1132 IP multicast)
     Received 509518 broadcasts (308 IP multicast)
     Received 472302 broadcasts (15 IP multicast)
     Received 562089 broadcasts (0 IP multicast)
     Received 304329 broadcasts (0 IP multicast)
     Received 320419 broadcasts (1055370 IP multicast) <= link to other
msfc
     Received 253866 broadcasts (79285 IP multicast)
     Received 207589 broadcasts (904958 IP multicast)
     Received 473552 broadcasts (3 IP multicast)
     Received 440555 broadcasts (0 IP multicast)
     Received 1291723 broadcasts (40 IP multicast)
     Received 0 broadcasts (0 IP multicast)
     Received 1573416 broadcasts (0 IP multicast)
     Received 431940 broadcasts (0 IP multicast)
     Received 2071880 broadcasts (83 IP multicast)
     Received 426213 broadcasts (0 IP multicast)
     Received 443926 broadcasts (0 IP multicast)
     Received 429584 broadcasts (0 IP multicast)
     Received 315648 broadcasts (0 IP multicast)
     Received 287898 broadcasts (0 IP multicast)
     Received 534388 broadcasts (128 IP multicast)
     Received 545230 broadcasts (0 IP multicast)
     Received 542563 broadcasts (0 IP multicast)
     Received 376464 broadcasts (8172 IP multicast)
     Received 378421 broadcasts (1 IP multicast)
     Received 373696 broadcasts (3 IP multicast)
     Received 318151 broadcasts (50 IP multicast)
     Received 296260 broadcasts (0 IP multicast)
     Received 0 broadcasts (0 IP multicast)
     Received 1100347 broadcasts (4960 IP multicast)
     Received 195736 broadcasts (0 IP multicast)
     Received 1134048 broadcasts (0 IP multicast)
     Received 23 broadcasts (0 IP multicast)
     Received 115132 broadcasts (0 IP multicast)
     Received 195576 broadcasts (128 IP multicast)
     Received 194162 broadcasts (0 IP multicast)
     Received 0 broadcasts (0 IP multicast)
     Received 272921 broadcasts (0 IP multicast)
     Received 274876 broadcasts (0 IP multicast)
     Received 0 broadcasts (0 IP multicast)
     Received 273252 broadcasts (0 IP multicast)
     Received 0 broadcasts (0 IP multicast)
msfc2# sh int | inc Input q
  Input queue: 0/75/0/7 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/3/5 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/3/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/6/551 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/3/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/1/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 1/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/4 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/1/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 1/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/1/2076 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/1/4 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/34/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/150/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/2/4 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/2531 (size/max/drops/flushes); Total output drops: 0
<=== link to the other msfc
  Input queue: 0/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/3/2729 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 1/75/0/3 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/2 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/6 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/3 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/1 (size/max/drops/flushes); Total output drops: 0
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
msfc2#


> Perhaps you can "debug standby" as the problem is happening and paste
> the output to the list?

Probably not unless I can tell my boss that I've got a pretty good idea of
what the problem is & how to fix it.
I think we're just going to leave multicast turned off & upgrade the core
sup1a/msfcs to sup720s.

Thanks,
Lee

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