Cisco 6500 - Manual (Page 46)

4-46
Cisco IOS Software Configuration Guide, Release 12.2SX
OL-13013-06
Chapter 4 Configuring Virtual Switching Systems
Configuring a VSS
Note Before changing PAgP dual-active detection configuration, ensure that all port channels with trust mode
enabled are in administrative down state. Use the shutdown command in interface configuration mode
for the port channel. Remember to use the no shutdown command to reactivate the port channel when
you are finished configuring dual-active detection.
To enable or disable PAgP dual-active detection, perform this task:
You must configure trust mode on the port channels that will detect PAgP dual-active detection. By
default, trust mode is disabled.
Note If PAgP dual-active detection is enabled, you must place the port channel in administrative down state
before changing the trust mode. Use the shutdown command in interface configuration mode for the port
channel. Remember to use the no shutdown command to reactivate the port channels when you are
finished configuring trust mode on the port channel.
To configure trust mode on a port channel, perform this task:
This example shows how to enable PAgP dual-active detection:
Router(config)# interface port-channel 20
Router(config-if)# shutdown
Router(config-if)# exit
Router(config)# switch virtual domain 100
Router(config-vs-domain)# dual-active detection pagp
Router(config-vs-domain)# dual-active detection pagp trust channel-group 20
Router(config-vs-domain)# exit
Router(config)# interface port-channel 20
Router(config-if)# no shutdown
Router(config-if)# exit
This example shows the error message if you try to enable PAgP dual-active detection when a trusted
port channel is not shut down first:
Router(config)# switch virtual domain 100
Router(config-vs-domain)# dual-active detection pagp
Trusted port-channel 20 is not administratively down.
To change the pagp dual-active configuration, “shutdown” these port-channels first.
Remember to “no shutdown” these port-channels afterwards.
This example shows the error message if you try to configure trust mode for a port channel that is not
shut down first:
Router(config)# switch virtual domain 100
Command Purpose
Step 1 Router(config)# switch virtual domain domain_id Enters virtual switch submode.
Step 2 Router(config-vs-domain)# dual-active detection pagp Enables sending of the enhanced PAgP messages.
Command Purpose
Step 1 Router(config)# switch virtual domain domain_id Enters virtual switch submode.
Step 2 Router(config-vs-domain)# dual-active detection pagp
trust channel-group group_number
Enables trust mode for the specified port channel.