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New Member

momentary outage

I recevied a report of a very brief outage on 3 seperate servers. I have about 10 switches and checked each one, the uptimes were all proper. CNA did not show any outstanding errors yet it cannot monitor my 4507 core switches.

I ran a sh diagnostics all of my ports are fine, there arent any errors on the interfaces.

the servers themselves show traffic during the outage times.

any ideas how to troubleshoot this further?

New Member

Re: momentary outage

This one will probably difficult to troubleshoot if not impossible.

Are all of your servers in the same VLAN? If so why did only three servers experience an outage? What I am trying to get at is that you will need to narrow it down to some commonality between these tree servers.

Are they the only servers in this VLAN? If yes it could be STP. Are they the only servers on this switch? Could be STP.

If these servers share switches and VLANs with other servers it might not be network related.

Check the logs on the servers to see if the NICs lost link.

Do you have a syslog server?

Kiwi has a free version you can then syslog at the debug level to the machie running Kiwi. Then the next time this problem arises you will have syslog entries.

Good luck.

New Member

Re: momentary outage

unfortunately its all 1 vlan.

i am seeing some buffer errors now that were not prevously seen. Cisco says these are typically caused by memory leaks in the ios, what else would cause this, is it a cause for concern?

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full-duplex, 100Mb/s

input flow-control is off, output flow-control is off

ARP type: ARPA, ARP Timeout 04:00:00

Last input never, output 00:00:01, output hang never

Last clearing of "show interface" counters 5d23h

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 4000 bits/sec, 6 packets/sec

1147099 packets input, 363077185 bytes, 0 no buffer

Received 1141 broadcasts (0 multicast)

0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog, 40 multicast, 0 pause input

0 input packets with dribble condition detected

9091970 packets output, 852391173 bytes, 1174 underruns

0 output errors, 0 collisions, 0 interface resets

0 babbles, 0 late collision, 0 deferred

0 lost carrier, 0 no carrier, 0 PAUSE output

1174 output buffer failures, 0 output buffers swapped out

New Member

Re: momentary outage

With everything in one VLAN it pretty much rules out STP.

Output buffer errors and memory leaks are both cause for concern. You could recover from memory leaks by rebooting - but that would only be a temporary solution as they will come back. Best bet is to update the IOS and then reboot.

Cisco Employee

Re: momentary outage

Please post the following:

show buffer

show proc mem

show mem sum

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