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Serial 0/0:0 is reset, line protocol is down

areynolds
Level 1
Level 1

Can anyone tell me what conditions cause a serial line to report being reset. We have a line problem so I have a good idea of the source of the problem but I am interested in what the interface is missing/receiving to cause this condition

Thanks

Andy

5 Replies 5

maher
Level 1
Level 1

Hi,

Basically, what I did is that try to apply local loopback at the controller. If the serial0/0:0 is up, line protocol is up (looped), no problem at the controller.Try to contact your telco provider.Ask them do loop and continue troubleshoot :)

regards,

maher

The interface comes up to a loop. I am trying to find out which conditions are not being met to cause an interface to show serial X\X:X is reset.

Is it that I am not getting keep alives? or something along those lines?. If i go to another router with a serial interface and diconnect the line I will get

serial X/X is down protocol is down. So what is happenning to cause it to go into reset

Thanks

andy

Kevin Dorrell
Level 10
Level 10

Could you post a show int please?

Kevin Dorrell

Luxembourg

Here's a show int ser0/0:0

Serial0/0:0 is reset, line protocol is down

Hardware is DSX1

Description: Global Crossing T1 to London EON# 465143/1

Internet address is 172.30.126.174/30

MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec,

reliability 252/255, txload 1/255, rxload 1/255

Encapsulation HDLC, loopback not set

Keepalive set (10 sec)

Last input 4d14h, output 4d14h, output hang never

Last clearing of "show interface" counters 4d14h

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 0/1/256 (active/max active/max total)

Reserved Conversations 0/0 (allocated/max allocated)

Available Bandwidth 1152 kilobits/sec

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

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

0 packets input, 0 bytes, 0 no buffer

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

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

0 packets output, 0 bytes, 0 underruns

0 output errors, 0 collisions, 13239 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions

Timeslot(s) Used:1-24, Transmitter delay is 0 flags

Thanks

Andy

I'm no expert in T1, but I would be looking for a problem with the framing and/or the linecode. I would check the configuration of the T1 controller vs. the parameters supplied by your provider. Just a guess, but I would have thought the subinterfaces would be held in reset until the line had synced correctly. Looks like the line has been reset on average once every 6 minutes since the counters were cleared.

Kevin Dorrell

Luxembourg

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