The ATM debug commands are implemented either at the interface level or at the system level. The debug command output at these levels is not very useful when the user is interested in a particular set of virtual circuits (VCs).

The Cisco IOS XE software has the infrastructure to support conditional debugging based on various filters that are set at the command-line interface (CLI). The conditional debugging infrastructure can filter out or suppress unwanted messages from the output of any existing debug command. The ATM Conditional Debug Support feature extends this infrastructure to support conditional debugging at the ATM VC level by extending the debug condition interface command with keywords that address specific virtual circuits. This feature can be implemented on top of conventional debugging, so that backward compatibility is ensured and at the same time applications can take advantage of conditional debugging where required. However, the extended debug condition interface command has priority over the older version of the command; that is, a debug condition setting using the older debug condition interface command will be discarded as soon as a new debug condition is enabled on a virtual circuit.

The following example shows how to enable an ATM interface, specify an IP address for the interface, enable conditional debugging for that interface with a VPI/VCI pair of 10/100, and verify that debugging has been enabled:

Enter configuration commands, one per line. End with CNTL/Z. 
Router(config)# interface atm 1/1/0.100 point-to-point
 
Router(config-if)# ip address 10.0.0.5 255.255.255.0 
Router(config-if)# pvc 10/100
 
Router(config-if-atm-vc)# no shutdown
 
Router(config-if)# exit
 
Router(config)# exit
 
Router# 
Router# debug atm state
 
ATM VC States debugging is on 
Router# debug condition interface ATM1/1/0 vc 10/100
 
Condition 1 set 
Router# 

The following example shows how to enable conditional debugging on a specific VCI. Note that when you enable conditional debugging on a specific VCI alone, the VPI value is automatically set to 0.

Router# debug condition interface atm 1/0 vc 4335 
Condition 1 set
Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)# interface atm 1/0
Router(config-if)# pvc 4335
Router(config-if-atm-vc)# end
Router#
*Jul 12 21:46:52.487: atmdx_setup_vc(ATM1/0): vc=5, vpi=0, vci=4335,  config_status=0
*Jul 12 21:46:52.487: atmdx_setup_cos(ATM1/0): vc=5, wred_name=, max_q=0
*Jul 12 21:46:52.487: ATM VC Debug: Condition 1, atm-vc 0/4335 AT1/0 triggered, count 1
*Jul 12 21:46:52.487: ATM1/0 Current Active VC count 4
 
*Jul 12 21:46:52.487:  ATM VC notification event 0
*Jul 12 21:46:52.487: atmdx_platform_set_vc_state(ATM1/0): Setting the VC 5 state to UP
*Jul 12 21:46:52.487: ATM: PVC activated, ATM1/0 VCD 5 (0/4335)
*Jul 12 21:46:52.487:  ATM VC notification event 2
*Jul 12 21:46:52.487: %SYS-5-CONFIG_I: Configured from console by console
Router# show atm vc
Codes: DN - DOWN, IN - INACTIVE 
 
           VCD /                                            Peak Av/Min Burst
Interface  Name         VPI   VCI Type    Encaps     SC     Kbps   Kbps Cells St
1/0        1              0    16 PVC     ILMI       UBR  149760              UP
1/0.10     4              0   100 PVC     SNAP       UBR  149760              UP
1/0        5              0  4335 PVC     SNAP       UBR  149760              UP
1/0.1      one            1    40 PVC     SNAP       UBR  149760              UP
1/0        2              3   100 PVC-A   SNAP       VBR    1000   1000     0 IN
4/ima1     1             23    34 PVC     SNAP       UBR       0              IN