[c-nsp] ARP oddness

Chuck Church chuckchurch at gmail.com
Mon Aug 22 11:15:11 EDT 2011


>
>
> -----Original Message-----
> From: Lee [mailto:ler762 at gmail.com]
> Sent: Friday, August 19, 2011 11:05 PM
> To: Chuck Church
> Cc: NSP - Cisco
> Subject: Re: [c-nsp] ARP oddness
>
> Unicast flooding?  You didn't say if the destination MAC address was
> known on the switch or no..
>
> Lee
>
>
> I'm starting to think this is unicast flooding now.  Noticed this just now:

VLAN0001 is executing the ieee compatible Spanning Tree protocol
  Bridge Identifier has priority 24576, sysid 1, address 001d.453d.f300
  Configured hello time 2, max age 20, forward delay 15
  We are the root of the spanning tree
  Topology change flag set, detected flag set
  Number of topology changes 913 last change occurred 15:02:50 ago
          from GigabitEthernet3/38
  Times:  hold 1, topology change 35, notification 2
          hello 2, max age 20, forward delay 15
  Timers: hello 0, topology change 22, notification 0, aging 15

 That 'topology change flag set' never seems to go away, despite the last
change timer getting up into the hours timeframe now.  I'm not sure why this
STP doesn't seem to want to iron itself out.  I'm going to have our vendor
move this to RSTP, which is our standard.  Still, not sure why it's doing
this, unless a device is constantly sending out TCNs?

Chuck


More information about the cisco-nsp mailing list