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how to check if serial interface is passing traffic

mahesh18
Level 6
Level 6

hi all,

how we can check if serial interface is passing traffic or not?

8 Replies 8

Jon Marshall
Hall of Fame
Hall of Fame

Mahesh

1) "sh ip int br" will show you whether the interface is up/up

2) "sh int s0/0" will show many packets are being received and transmitted.

3) Try pinging something that is reachable via the serial interface.

Jon

Hi

this is stat of int

Serial1/0 is up, line protocol is up

Hardware is M4T

Description: T1 Glaxo link Centennial

Internet address is 10.39.1.21/30

MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,

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

Encapsulation HDLC, crc 16, loopback not set

Keepalive set (10 sec)

Restart-Delay is 0 secs

CRC checking enabled

Last input 00:00:01, output 00:00:02, output hang never

Last clearing of "show interface" counters 00:25:17

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 0 bits/sec, 1 packets/sec

749 packets input, 80980 bytes, 0 no buffer

Received 177 broadcasts, 0 runts, 0 giants, 0 throttles

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

1519 packets output, 149171 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up

how can we chek from here

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

5 minute output rate 0 bits/sec, 1 packets/sec

at the moment there is no traffic passing thru serial interface as u can see no data.

Rate if this helps!!!

i did ping to some ips

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 0 bits/sec, 1 packets/sec

5 minute output rate 1000 bits/sec, 1 packets/sec

1072 packets input, 114662 bytes, 0 no buffer

Received 261 broadcasts, 0 runts, 0 giants, 0 throttles

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

2243 packets output, 218569 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up

still it shows above so no data is passing right??

Mahesh

From this router can you ping the other end of the link ie.

ping 10.39.1.22

Jon

sdoremus33
Level 3
Level 3

To verify if traffic is passing over serial interface

sh ip interface serial0/0

extended ping

sh ip int serial0/0

also sh controller serial0/0

Hi,

Here's the counter before PING -

749 packets input, 80980 bytes, 0 no buffer

1519 packets output, 149171 bytes, 0 underruns

Here's after PING -

1072 packets input, 114662 bytes, 0 no buffer

2243 packets output, 218569 bytes, 0 underruns

There is an increase in received and transmitted packets which proves that traffic is passing through the interface.

Do a continuous ping to some device connected across the serial interface and keep track of the above lines from the show interface output.

If you see the count increasing then the traffic is passing through that particular interaface.

-> Sushil

Mahesh

I was going to make the same point that Sushil makes about the counters in an earlier post showing:

749 packets input, 80980 bytes, 0 no buffer

Received 177 broadcasts, 0 runts, 0 giants, 0 throttles

1519 packets output, 149171 bytes, 0 underruns

and a later post showing that the input counter and the output counter and the broadcast counter had gone up.

1072 packets input, 114662 bytes, 0 no buffer

Received 261 broadcasts, 0 runts, 0 giants, 0 throttles

2243 packets output, 218569 bytes, 0 underruns

That would seem to indicate that the interface was passing data.

Another test would be to do a traceroute to the IP on the other end of the interface or to some destination reachable through the interface and see if the next hop address on the first hop is the address on the other end of the connection.

Perhaps it would help us if you can explain why you are asking this. Is there some problem that suggests that the interface is not working?

HTH

Rick

HTH

Rick
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