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New Member

ciscoworks affecting the network


we are currently using LMS 3.1 & Campus Manager 5.1. Each time Campus Manager

is doing the data collection (every 4 hours) we are experiencing network failure ...loosing pings on our 3750

stack.(where lms and all servers are connected).

Each time data collection is running

the switch is displaying "%SPANTREE-2-LOOPGUARD_BLOCK: Loop guard blocking port Port-channel1 on VLAN0016"

and then, unblock for all vlans on the trunq (port-channel).

This flash will last for a second or 2

but that's enough for killing people connections.

Any ideas ?

Cisco Employee

Re: ciscoworks affecting the network

It is possible some of the SNMP requests being made are triggering problems. In order to diagnose the problem, you should open a TAC service request with the show tech from a problem switch. The troubleshooting process will also involve getting a sniffer trace of the SNMP traffic to the switch at the time network connectivity is lost (and the syslog messages are generated) in order to identify the problem, and possible design a workaround.

New Member

Re: ciscoworks affecting the network

i've got this message for each vlan on the switch :

2009-06-30 15:58:14 Local7.Debug community=public, enterprise=, enterprise_mib_name=stpxNotifications, uptime=-768761795, agent_ip=, generic_num=6, specificTrap_num=3, specificTrap_name=stpxLoopInconsistencyUpdate, version=Ver1,, stpxSpanningTreeType.0=rapidPvstPlus

i've got loopguard block and unblock

for each vlan.

seems like the switch is seeing

a topology change

Cisco Employee

Re: ciscoworks affecting the network

That is correct, but what is not clear is why that is occurring. You could certainly be running to a bug triggered by the SNMP polling, but more troubleshooting will be required.

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