Troubleshooting guide

12-8
ATM and Layer 3 Switch Router Troubleshooting Guide
OL-1969-01
Chapter 12 Troubleshooting Layer 2 Interfaces
Troubleshooting Layer 2 Switching
Step 6 Use the show epc patricia interface FastEthernet interface command with the mac detail parameters.
Switch# show epc patricia interface FastEthernet 12/0/1 mac detail
.
(Information Deleted)
.
7# MAC addr:0090.21bb.bbbb IF Number:58 Entry:Remote
Learned 10450 times used
CAM location: 101D
8# MAC addr:0010.e3aa.aaaa IF Number:43 Entry:Local
Learned 0 times used
CAM location: 0FF8
Total number of MAC entries: 8
Step 7 Verify that the information from this command is consistent with the command outputs in Step 5.
If there are inconsistencies or non-zero invalid entries in the tables, you can use the clear bridge
command to rebuild the tables.
Step 8 Check the Entry field.
Interface Number 58 has learned of this entry via the flooding from IF Number 42 and it is marked as
Remote. Interface number 43 has learned these entries as local entries, which is typical bridge behavior.
Note Entries marked as MyMac are for internal use. These are static entries and are for spanning tree
BPDUs and CDP. The MAC address marked as HSRP is the actual BIA Mac address of the port. This
entry is only present if there is a BVI defined for that bridge group.
Verify that the information from the show epc patricia command output is consistent with the command
outputs in Step 4.
If there are inconsistencies or non-zero invalid entries in the tables, you can use the clear bridge
command to rebuild the tables.
Caution Use the clear bridge command carefully. It causes a temporary increase in switch router activity
which can lead to traffic disruptions.
Step 9 Use the show epc patricia interface GigabitEthernet interface command with the vlan number and
details parameters.
Switch# show epc patricia interface GigabitEthernet 11/0/1 vlan 1 detail
15# MAC addr:0090.21bb.bbbb IF Number:58 Entry:Local
Learned 0 times used
CAM location: 1034
16# MAC addr:0010.e3aa.aaaa IF Number:43 Entry:Remote
Learned 6029 times used
CAM location: 101B
Step 10 Check the Entry field. The Entry field descriptions are the same as those in Step 8.
Verify that the information from the show epc patricia command output is consistent with the command
outputs in Step 4.
If there are inconsistencies or non-zero invalid entries in the tables, you can use the clear bridge
command to rebuild the tables.