SNMP Error Timeout

[Anonymous]

Have a customer that has two different sites with a couple S8's at the core of one and S4's at the core of another.

The edge consists of multiple stacks of C5's which the top switch being a C5K for 10gb.

There seems to be a couple, out of the manystacks that persistently give the following error:

SNMP Contact Lost: No SNMP reply from device 192.168.xxx.xx caused by SNMP Error: Timeout[4098], last uptime was 21 Days 23:14:26.4

When Netsight looses SNMP contact to the switch you can still ping and SSH to it, and no other adverse affect seems to be happening to the switch then what seems random lose in polling.

When an event briefly happened I was able to get onto the device and tried to ping the IP address of the Netsight server, which failed! I wasn't able to do anymore testing before it came back online.

The uplink ports consist of one 1 x 10gb and 2 x 1GB as a lag. MSTP is configured with the data vlan using the 10Gb and the lag used for the voice vlan.

Have looked at spanning, and there has been no topology changes, the ports have remained continually up and show no errors in rmon stats.

Not sure if anyone has seen this before and can provide any suggestions?

Many thanks

[James_A]

I've turned off the tx flowcontrol on the network card, and now it's dropping packets (dropped_no_small_buffer is increasing) so it's looking like a problem with the host itself. I do have a ticket open (01047722) but it doesn't look like a problem on the network side. Thanks, James

[Jason_Parker]

If you call into the GTAC to open a ticket then we can assist you. Just mention this site (HUB) and then ask them to make me a contributor or co-owner
Then I can assist over the phone. This would be needed to document the situation
Thanks
Jason Parker

[Jason_Parker]

Clear port advertise tg.1.3 pause would work but a reminder that the link will drop for a second

[James_A]

I've been getting SNMP error timeouts for a while now, and I had a look last week on our S4, and the port our Linux router was connected to was occasionally increasing. That router had a hardware failure and now we're running on the backup router which is connected to a G3 and now I'm seeing nearly constant increases in pause frames. From today
G3(su)->show port flowcontrol tg.3.3 port TX Pause Count RX Pause Count-------- --------------- -------------- tg.3.3 0 14858653and about 5 hours later:
G3(su)->show port flowcontrol tg.3.3 port TX Pause Count RX Pause Count-------- --------------- -------------- tg.3.3 0 17704492For reference, the routers have 10Gb Myricom cards, and today are pushing 800-1200Mbps.

[Jason_Parker]

Run the command show igmpsnooping MFDB (multicast filtering data base) to see what you are running
Note:
If there is no querier on the network then the igmp commands are really not helpful and also some companies that use multicast may have the communication between controller and AP's

But in most cases a sniffer(wireshark is free) can help you isolate any traffic concerns.

The easy way to handle this is to document the numbers on each switch and then select ports not enabled(or connected) and run the command clear port advertise ge.x.x pause on the port

Another option is to set flowcontrol disabled(This does the same thing as clear port advertised pause in a way that the links would be dropped and reconnected).

Jason