Troubleshooting guide

12-6
ATM and Layer 3 Switch Router Troubleshooting Guide
OL-1969-01
Chapter 12 Troubleshooting Layer 2 Interfaces
Troubleshooting Layer 2 Switching
Figure 12-3 Broadcasting CAM Updates
To confirm that Broute VC 0 is up, use the show atm vc cast p2mp interface fastethernet
slot/subslot/port command as shown in the following example.
Switch# show atm vc cast p2mp interface fastethernet 0/0/0
Interface VPI VCI Type X-Interface X-VPI X-VCI Encap Status
FastEthernet0/0/0 0 202 PVC FastEthernet0/0/1 0 227 UP
FastEthernet0/0/2 0 228 UP
Using the cross-connect VCI information from the previous output, confirm that Broute VC 0 is
configured on the other interfaces in the bridge group use the show atm vc traffic interface fastethernet
slot/subslot/port 0 X-VCI command as shown in the following examples:
Switch# show atm vc traffic interface fastethernet 0/0/0 0 202
Interface VPI VCI Type rx-cell-cnts tx-cell-cnts
FastEthernet 0 202 PVC 0 0
Switch# show atm vc traffic interface fastethernet 0/0/1 0 227
Interface VPI VCI Type rx-cell-cnts tx-cell-cnts
FastEthernet 0 227 PVC 0 0
Switch# show atm vc traffic interface fastethernet 0/0/2 0 228
Interface VPI VCI Type rx-cell-cnts tx-cell-cnts
FastEthernet 0 228 PVC 0 0
Figure 12-4 is an example network of two Layer 2 switches, and is used in the following troubleshooting
steps.
Figure 12-4 Layer 2 Troubleshooting Example Network
The following are the processes used to troubleshoot Layer 2 switching connections:
• Check the route processor “View” of the spanning tree.
• Verify information on interface modules.
• Verify VC status between ports.
P2MP
root
50434
FE 0/0/0
VC 0, 202
FE 0/0/1
VC 0, 227
FE 0/0/2
VC 0, 228
Host A Catalyst 8540-2Catalyst 8540-1 Host B
ISL Port Channel
MAC:
00:10.e3:aa...
MAC:
00:90.21:bb...
MAC:
00:90.21:dd...
MAC:
00:90.21:ff...
MAC:
00:90.21:cc...
MAC:
00:90.21:ee...
50252