Dual-Active Detection (Virtual Switch) - Cisco Catalyst 4500 Series Command Reference Manual

dual-active detection (virtual switch)

dual-active detection (virtual switch)
To enable and configure dual-active detection, use the dual-active detection command in virtual switch
configuration submode. To disable dual-active detection, use the no form of this command.
Syntax Description
pagp
trust channel-group
num
Defaults bfd and pagp are enabled.
trust is disabled.
Command Modes Virtual switch configuration submode (config-vs-domain)
Command History Release
Cisco IOS XE 3.4.0SG and
15.1(2)SG
Usage Guidelines
If PAgP is running on the MECs between the VSS and its access switches, the VSS can use enhanced
PAgP messaging to detect dual-active scenario. The MEC must have links from both chassis of the VSS
to the access switch. By default, PAgP dual-active detection is enabled. However, the enhanced messages
are only sent on channel groups with trust mode enabled.
If you configure the fast hello dual-active detection mechanism, you must also configure dual-active
interface pairs to act as fast hello dual-active messaging links.
When you enter the optional trust channel-group num keywords and argument, the following applies:
•
•
•
Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.4.0SG and IOS 15.1(2)SG)
2-234
dual-active detection {pagp [trust channel-group num]}
no dual-active detection {pagp}
Configures Port Aggregation Protocol (PAgP) as the dual-active
detection method. Default: enabled.
(Optional) Specifies the EtherChannel/port bundling to be used for
PAgP dual-active detection. Range: 1 to 256. Default: disabled.
You can configure trust mode on a port channel even if there are no interfaces on the port channel
or the port channel is a protocol type other than PAgP. The trust mode status is displayed in the show
pagp dual-active command output, but no interfaces are displayed.
Configuring trust mode requires that the port channel exists. If the port channel does not exist, the
following error message is displayed:
Router(config-vs-domain)# dual-active trust pagp channel-group 30
Port-channel 30 not configured
If a trusted port is deleted, the trust-mode configuration is deleted and the following warning
message is displayed:
Port-channel num is a trusted port-channel for PAgP
dual-active detection. Restricting this
port-channel has deleted the dual-active trust
Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
Modification
Support for this command was introduced on the Catalyst 4500 series
switch.
OL-27596 -01