Troubleshooting guide

5-2
ATM and Layer 3 Switch Router Troubleshooting Guide
OL-1969-02
Chapter 5 Troubleshooting Switch Router ATM Interface Connections
Performing Basic Interface Checks
• Do the transmit and receive cable pairs match?
• Are the cables the proper type?
Note Just because the connector fits, does not mean the wires in the cable are necessarily cross-connected
correctly, and the cable is not necessarily the correct type.
• Are the cables reliable? If not, try a different cable.
• Are the interfaces on both sides of the cables enabled and in no-shutdown mode?
• Are the interfaces configured properly (for example, framing mode, line coding, scrambling mode)?
• Are the interfaces on both ends of the cable the same type of interface?
Use the following command to check the ATM physical interface configuration:
Follow these steps to troubleshoot the physical interface:
Step 1 Use the show interfaces atm card/subcard/port command to display status and error information about
an interface.
Switch# show interfaces atm 1/0/0
ATM1/0/0 is up, line protocol is up
Hardware is oc3suni
MTU 4470 bytes, sub MTU 4470, BW 156250 Kbit, DLY 0 usec, rely 255/255, load 1/255
Encapsulation ATM, loopback not set, keepalive not supported
Last input 00:00:00, output 00:00:00, 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
527152 packets input, 27939056 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
527246 packets output, 27944038 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 or constant bit rate (CBR) 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.
Command Purpose
show interfaces atm card/subcard/port Shows the status of the physical interface.