Operating instructions

Chapter 8. Cisco Systems IGESM troubleshooting 219
show int trunk
Figure 8-9 shows some of the attributes of the show int trunk command.
Figure 8-9 Output of sh int trunk command
show etherchannel summary
Figure 8-10 shows the output of a show eth sum command. It is important to check the health
of an aggregation, and not just whether it can pass a simple ping test.
Figure 8-10 Output of show eth sum commands
• Lets you know what VLANs can be carried and are being carried on
trunk ports
cigesm_t#sh int trunk
Port Mode Encapsulation Status Native vlan
Gi0/15 on 802.1q trunking 30
Po1 on 802.1q trunking 1
Po2 on 802.1q trunking 1
Port Vlans allowed on trunk
Gi0/15 30,4094
Po1 1-29,31-4093
Po2 1-29,31-4093
Port Vlans allowed and active in management domain
Gi0/15 30,4094
Po1 1-2,110,333,444,777-779
Po2 1-2,110,333,444,777-779
Port Vlans in spanning tree forwarding state and not pruned
Gi0/15 30,4094
Po1 1-2,110,333,444,777-779
Po2 2,110,333,444
Native VLAN in use on trunk link
VLANs that CAN be carried on trunk
VLANs that ARE carried on trunk
Make sure any VLANs you want
carried show up in this list on the
proper interfaces. If they do not,
make sure VLAN exists and that
it’s assigned to be carried on the
desired interfaces
VLANs on trunk not being blocked by spanning-tree
• Important to monitor the health of the Etherchannel
connection
cigesm_t#sh eth sum
Flags: D - down P - in port-channel
I - stand-alone s - suspended
H - Hot-standby (LACP only)
R - Layer3 S - Layer2
u - unsuitable for bundling
U - in use f - failed to allocate aggregator
d - default port
Number of channel-groups in use: 2
Number of aggregators: 2
Group Port-channel Protocol Ports
------+-------------+-----------+----------------------
1 Po1(SU) LACP Gi0/17(Pd) Gi0/18(P)
2 Po2(SU) LACP Gi0/19(P) Gi0/20(Pd)
SU = good
Anything else = problem
P or Pd = good
Anything else = problem
This example shows a switch with
two Etherchannels bundles, one
using ports 17 and 18 and one
using ports 19 and 20
Shows ports assigned to
bundle