Shutdown on Serial interfaces

[abouzidzineb]

Hi,

I installed the Leased Line based WAN network but I have the following behavior:

some serial interfaces become administratively down with no human intervention.

When I execute the "no shutdown" on the interface,the interface becomes up up and works well for a period of a week, then it become newelly "administratively down".

Is this due to the Leased Line or to other reasons?, the encapsulation is PPP.

Thank you in advance

[Josef Oduwo]

What equipment are you running?

Do a "show inter" to see the status of your interface and perhaps post it here. Very generally, if the int goes administratively down, you are looking at a problem with the interface itself: bad or worn points etc etc.

Don't forget to rate... :)

[abouzidzineb]

I have a 3745 Cisco Router and the show interface command result is as follow:

Serial0/0 is administratively down, line protocol is down

Hardware is CD2430 in sync mode

Description: Link to remoteSite

Internet address is 10.1.1.1/30

MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec,

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

Encapsulation PPP, LCP Closed

Closed: CDPCP, IPCP, loopback not set

Last input 21:32:48, output 14:56:08, output hang never

Last clearing of "show interface" counters 2w2d

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 0/15/32 (active/max active/max total)

Reserved Conversations 0/0 (allocated/max allocated)

Available Bandwidth 48 kilobits/sec

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

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

445804 packets input, 36991850 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 5 giants, 0 throttles

8 input errors, 2 CRC, 0 frame, 0 overrun, 0 ignored, 6 abort

903525 packets output, 88882778 bytes, 0 underruns

0 output errors, 0 collisions, 5813 interface resets

0 output buffer failures, 0 output buffers swapped out

12 carrier transitions

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

Best Regards

[krozier]

Hi,

From looking at you "Show Int" output you definately have a serial line communication problem.The interface resets and the carrier transition is pointing clocking problem on the line. I would suggest contacting your T1 provider and performing test on the line.You could also perform a loopback test on the local hardware to make sure the the hardware at the site is not bad.

Hopes this helps

Kersean Rozier

[abouzidzineb]

Thank your Kersean Rozier for your response,

Can you please tell what parameter that indicate that there is a line problem according to the "show ip" result.

Best Regards,

[krozier]

These two lines are indicators of problems on the Serial line.

5813 interface resets <---This line is really HIGH

12 carrier transitions

Normally, my routers that have been up a year only have at most 3 interface resets.

Kersean Rozier

[bigbhai]

Hi,

This mainly happens due to bug with the IOS compatibilty so please upgrade the ios or install the same ios once again and check it out.