Intermittent connection status of devices on map

Unanswered Question
Feb 28th, 2008


Our client is a hotel with about 600 guest rooms. We configured the switches having 1 vlan per room and our management vlan is vlan 1000. We also configured spanning-tree instances due to so many vlans. We have a total of 35 switches for their network infrastructure which includes 2 units of Cisco 3750 stacked and the rest are Cisco 2960 switches deployed as either distribution and access layer. Configuration-wise everything is just fine but on Ciscoworks LMS, there are instances that it shows in the topology map that a particular switch is down but in reality the users connected to it is having no problems. This occurs randomly, in no particular switch at no specific time. The down switches though comes up after some time. The Ciscoworks LMS 2.6 server is connected directly to the core switch as member of vlan 1000.

Need help on this matter so that monitoring of the switches would be reliable.

I have this problem too.
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Joe Clarke Thu, 02/28/2008 - 22:40

First, Campus Manager is not a fault management application. You should not infer than just because a switch shows as red on the topology map that this switch is down. A red switch means that at the time Campus last polled this switch, it did not respond to SNMP in a timely manner. This may be due to the fact that the switch was handling other higher priority tasks. Additionally, Campus' polling interval is two hours by default which is no where near real time enough for fault management.

Debugging this problem can be tricky since it happens randomly. It involves checking what the switch is doing at the time the SNMP poll fails. You will also need a sniffer and/or debug snmp packet output to determine if the SNMP traffic is actually making it to the switch. Once the cause of the missed SNMP poll is determined, it may be possible to tweak things to allow it to succeed.

All that said, you should be using a true fault management application to alert you when the device is actually down. Such apps include DFM, HPOV, NetView, Whats Up Gold, etc.

benjo.rulloda Sun, 03/02/2008 - 16:36

Hi Joe,

Thanks for your response. Does this mean we have to use another application to replace the Topology Services map of Campus Manager? We have already set the polling interval to 5 minutes but the status is still the same.

Joe Clarke Sun, 03/02/2008 - 17:56

Topology Services is the only mapping application in LMS. However, it is geared toward network documentation and not fault management. There will be some fault management capabilities added to it by integrating it more with DFM in future releases.

benjo.rulloda Mon, 03/03/2008 - 16:17

Hi Joe,

Can we use Cisco Network Assistant (CNA) instead to replace the mapping capability of LMS or would it just have the same effect like the one we're having on Topology Services?

Joe Clarke Mon, 03/03/2008 - 16:51

I believe CNA might have more fault capabilities, but I don't have much experience with it. It certainly does not have the supported device range of Campus Manager, though.

benjo.rulloda Mon, 03/03/2008 - 16:59

What can you suggest Joe that we use as a reliable tool for mapping our devices?

Joe Clarke Mon, 03/03/2008 - 17:16

In terms of fault, the ones I already listed (e.g. HPOV NNM, NetView, and Whats Up Gold). Orion's SolarWinds also does mapping and fault.

jbarger Wed, 04/23/2008 - 10:03

On a side note you probably need to increase the timeout for SNMP. This will not help you with deteremining downtime but will keep all your boxes green on topology map. If you have a Linux box I highly recommend NMIS. It tracks utiliztaion on all switchports that have a description and can send alerts. The main dashboard is all green if everything is up. Since it is web based you can monitor the system remotely easily...


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