Cisco Support Community
Community Member

WAN interface down/up twice today...

Hi All,

My WAN interface was reported down by the network level 1 support but seems up when i went in to the router. I tried to check the log but didn't see any flips. Could it be due to the CRC error or input error like below?

Or wat could be the reason ?

Interface S0/0:

Last clearing of "show interface" counters 3w0d

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

Queueing strategy: weighted fair

Output queue: 0/1000/64/0 (size/max total/threshold/drops)

Conversations 0/36/256 (active/max active/max total)

Reserved Conversations 0/0 (allocated/max allocated)

Available Bandwidth 1158 kilobits/sec

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

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

762648 packets input, 107166376 bytes, 0 no buffer

Received 214659 broadcasts, 0 runts, 0 giants, 0 throttles

211 input errors, 211 CRC, 83 frame, 8 overrun, 0 ignored, 95 abort

827359 packets output, 327673463 bytes, 0 underruns

0 output errors, 0 collisions, 14 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions

DCD=up DSR=up DTR=up RTS=up CTS=up


Re: WAN interface down/up twice today...

you have not cleared counters for quite sometime now, so it's difficult to say that whether it happens due to crc/input errors. clear counter on the interface and check if errors are incrementing or not.

you can see link up/down messages in log only if you have enabled SNMP trap for recording link status. if you have enabled then you should see log message whenever link is going up/down even for a second.

if you ave EIGRP/OSPF peer estabalished over this link, then you can check show ip eigrp neighbor or show ip ospf neighor which will tell you since when peer are estabalished, if link have flapped, session will reset and you can come to know about that.

HTH ... rate if it does ..

CreatePlease to create content