Troubleshooting guide

E-4
ATM and Layer 3 Switch Router Troubleshooting Guide
OL-1969-01
Appendix
Architecture Problems
If you find evidence of a bad line, you can isolate the problem using hard or soft loopbacks. For loopback
test information refer to “Performing OAM Loopback Tests” section on page 5-6.
RAI (Remote Alarm Indication)
Note FERF (far-end receive failure) and RAI (remote alarm indication) are equivalent.
RAI indicates a problem between the ATM switch router interface transmitter and the far end receiver,
but it may not be in the segment between the ATM switch router and the adjacent node.
Follow these steps to correct an RAI alarm:
Step 1 Connect an external loopback cable to the port. If there are no alarms, the problem is not with the ATM
switch router.
Step 2 Examine adjacent network devices and check for LOS or LOF alarms.
Architecture Problems
This section describes some hardware and software architecture problems you might find on your ATM
switch router, and provides steps you can take to correct them.
Gigabit Ethernet Interface NOBUFFER Error
If you have a Gigabit Ethernet interface on an ATM switch router connected to an interface on an
Ethernet switch interface, you might see following console error message:
%AAL5-3-NOBUFFER: No reassembly buffer to receive pkt , vpi [dec], vci [dec]
This error occurs when the buffer space allocated for a Gigabit Ethernet interface is temporarily
exhausted, causing the interface to begin dropping packets.
The following are some processor traffic types that use these buffers and could cause this problem:
• Routing protocol traffic
• Multicast traffic
• ICMP, ARP, TTL expired traffic
• IPX RIP/SAP updates
• Bridging: BPDUs
• SNMP traffic
Follow these steps to troubleshoot the NOBUFER error problem on a Gigabit Ethernet interface:
Step 1 Enter the show interfaces card/subcard/port command for the Gigabit Ethernet interface associated
with the VC listed in the error message.
Switch# show interfaces GigabitEthernet 1/0/0