Troubleshooting guide

9-6
ATM and Layer 3 Switch Router Troubleshooting Guide
OL-1969-01
Chapter 9 Troubleshooting CES Connections and Network Clocking
Initial Troubleshooting of CES
Step 3 Check the Underflow and Overflow fields to confirm that the network clocking is synchronized.
Buffer overflows and underflows indicate a slight clocking difference between the devices. Buffer
overflows occur when the transmitting device is faster than the receiving device; such a condition results
in frame drops. Buffer underflows occur when the transmitting device is slower than the receiving
device; such a condition results in frame resends. Check with your service provider to reduce the cell
delay variation (CVD).
Step 4 Check the Src and Dst fields for the correct addresses.
Use the show atm status, show ces status, show atm address, and show ces address commands to
confirm the source and destination address configuration.
For detailed interface configuration information about CES, refer to the “Configuring Circuit Emulation
Services” chapter in the ATM Switch Router Software Configuration Guide. For detailed physical
interface troubleshooting information, see the “Troubleshooting CES T1 and CES E1 Interfaces” section
on page 5-46.
Follow these steps to confirm the CES interface configuration on the ATM switch router:
Step 1 Use the show ces circuit command to confirm the connection of the CES interfaces.
Switch# show ces circuit
Interface Circuit Circuit-Type X-interface X-vpi X-vci Status
CBR3/1/0 0 Passive SoftVC ATM-P3/1/3 0 3088 UP
CBR3/1/1 0 Passive SoftVC ATM-P3/1/3 0 2064 UP
CBR3/1/2 0 Active SoftVC ATM-P3/1/3 0 1040 UP
CBR3/1/3 0 Active SoftVC ATM-P3/1/3 0 16 UP
Switch#
Step 2 Check the Circuit-Type field. It should contain the correct type for the circuit.
Step 3 Check the X-interface field. It should contain the correct destination interface for the circuit.
Step 4 Check the Status field. It should read “UP.”
If the rest of the fields for the interface are correct but the status is “DOWN,” then check the X-interface
status using the show interfaces command. If the interface is administratively down, use the
no shutdown command to reenable it.
If you determine that the physical interface is configured incorrectly, refer to the “Configuring
Interfaces” chapter in the ATM Switch Router Software Configuration Guide.
For detailed interface configuration information about CES, refer to the “Configuring Circuit Emulation
Services” chapter in the ATM Switch Router Software Configuration Guide.