Troubleshooting Asymmetric Port Channels - Cisco Nexus 1000V Troubleshooting Manual

Chapter 10 Port Channels and Trunking
S e n d d o c u m e n t c o m m e n t s t o n e x u s 1 k - d o c f e e d b a c k @ c i s c o . c o m .
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Example 10-1
Example 10-1 show port-channel summary Command
n1000v# show port-channel summary
Flags:
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Group Port-
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Troubleshooting Asymmetric Port Channels

When troubleshooting asymmetric port channels, follow these guidelines:
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OL-28795-01
show port-channel internal event-history interface ethernet slot-number
show system internal ethpm event-history interface port-channel channel-number
show system internal ethpm event-history interface ethernet slot-number
show vlan internal trunk interface ethernet slot-number
show vlan internal trunk interface port-channel channel-number
debug port-channel error
module vem module-number execute vemcmd show port
module vem module-number execute vemcmd show pc
module vem module-number execute vemcmd show trunk
shows output of the show port-channel summary command.
D - Down P - Up in port-channel (members)
I - Individual H - Hot-standby (LACP only)
s - Suspended r - Module-removed
S - Switched R - Routed
U - Up (port-channel)
Type
Channel
Po1(SU) Eth
Po2(SU) Eth
Use APC when you want to configure a port channel whose members are connected to two different
upstream switches.
APC depends on Cisco Discovery Protocol (CDP). Make sure CDP is enabled on VSM and upstream
switches.
Physical ports within an APC get assigned subgroup IDs based on the CDP information received
from upstream switches.
A user can manually configure subgroup IDs in interface configuration submode.
Make sure that you configured sub-group CDP either with a port profile or on the port channel
interface.
Ports in APC will come up only when they are assigned subgroup IDs manually or through CDP.
Issue the show cdp neighbors command on the VSM and check the output.
Once the ports came up, check that ports are put in the correct sub-groups by issuing the module
vem module-number execute vemcmd show pc command on the VEM.
Use the debug port-channel trace command to collect information.
Protocol Member Ports
NONE Eth3/4(P)
NONE Eth3/2(P)
Cisco Nexus 1000V Troubleshooting Guide, Release 4.2(1)SV2(2.1)
Troubleshooting Asymmetric Port Channels
Eth3/6(P)
10-3