S0/0/0 T1, lots of input errors

Unanswered Question
Nov 9th, 2007

I have a point to point t1. on either router i am getting a lot of input errors on the s0 int. Are these errros something i should be worried about?below is the show int:

Router#show int s0/0/0

Serial0/0/0 is up, line protocol is up

Hardware is GT96K with integrated T1 CSU/DSU

Description: Connection to ATLANTIC

Internet address is

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

reliability 255/255, txload 42/255, rxload 43/255

Encapsulation HDLC, loopback not set

Keepalive set (10 sec)

Last input 00:00:09, output 00:00:04, output hang never

Last clearing of "show interface" counters 2w0d

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 4074

Queueing strategy: Class-based queueing

Output queue: 0/1000/64/3758 (size/max total/threshold/drops)

Conversations 0/222/256 (active/max active/max total)

Reserved Conversations 0/0 (allocated/max allocated)

Available Bandwidth 630 kilobits/sec

2 minute input rate 261000 bits/sec, 172 packets/sec

2 minute output rate 258000 bits/sec, 165 packets/sec

142539815 packets input, 2040485932 bytes, 0 no buffer

Received 149873 broadcasts, 0 runts, 0 giants, 0 throttles

27438 input errors, 27438 CRC, 12478 frame, 5819 overrun, 0 ignored, 21471


136220445 packets output, 1710436281 bytes, 0 underruns

0 output errors, 0 collisions, 42 interface resets

0 output buffer failures, 0 output buffers swapped out

8 carrier transitions

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

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royalblues Fri, 11/09/2007 - 11:35


The interface counters have not been cleared for more than 2 weeks and there are 42 interface resets as well in addition to the input & CRC errors

Clear the counters and check whether you still see these errors. These errors are mainly due to noisy line, Bad cable or faulty equipment

Have a look at the following link for troubleshooting serial lines




kpgwinnup Fri, 11/09/2007 - 12:04

here are some of my ping outputs from one router to the other. they look way too high.

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/11/20 ms

Success rate is 100 percent (5/5), round-trip min/avg/max = 16/19/20 ms

Success rate is 100 percent (5/5), round-trip min/avg/max = 20/20/24 ms

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/11/16 ms

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/16/24 ms

Success rate is 100 percent (5/5), round-trip min/avg/max = 16/17/20 ms

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/14/20 ms

Paolo Bevilacqua Fri, 11/09/2007 - 14:06


Agrwe with Narayan, but also consider, only about 0.0002% of input packets were received with errors. That is a very small number.

Especially if the errors are not increasing anymore, it could have been due to a transient condition on the circuit, and you do not need to worry about it.

The ping times you observed are also perfectly normal and the delay variance represent the time in queue due to congestion.

Hope this helps, please rate post if it does!


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