Troubleshooting guide

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ATM and Layer 3 Switch Router Troubleshooting Guide
OL-1969-02
Chapter 5 Troubleshooting Switch Router ATM Interface Connections
Troubleshooting T1 and E1 Interfaces
Follow these steps to troubleshoot the T1 and E1 physical interface:
Step 1 Use the show interfaces atm card/subcard/port command to check the T1 and E1 interface
configuration.
Switch# show interfaces atm 0/1/0
ATM0/1/0 is down, line protocol is down
Hardware is t1suni
MTU 4470 bytes, sub MTU 0, BW 1500 Kbit, DLY 0 usec, rely 0/255, load 1/255
Encapsulation ATM, loopback not set, keepalive not supported
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
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, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
Switch#
Step 2 Check the ATM field to see whether the interface is up.
If down, check for the following:
• Disconnected or faulty cabling—Check cables.
• Hardware failure—Swap hardware.
If administratively down, the interface has been administratively taken down. Use the no shutdown
interface configuration command to reenable the interface.
Step 3 Check the line protocol field to see that the status is up.
If the status is down, check for the following:
• The line protocol software processes might have determined that the line is unusable. Try swapping
the cable.
• The local or remote interface might be misconfigured. Check the interface configuration.
• Clocking might be misconfigured or the source interface might have failed. Refer to the “Initially
Configuring the ATM Switch Router” chapter in the
ATM Switch Router Software Configuration Guide.
• Hardware might have failed. Try swapping the port adapter.
Step 4 Check the Encapsulation field. Confirm that the encapsulation method matches the interface type.
Step 5 Check the Last input and Last output fields. They show the number of hours, minutes, and seconds since
the last packet was successfully received or transmitted by the interface.
Step 6 Check the output hang field. It shows the number of hours, minutes, and seconds since the last reset
caused by a lengthy transmission.