Cisco Catalyst 4500 Series Software Configuration Manual page 818

Displaying EtherChannel to a Virtual Switch System
Figure 27-1
Virtual switch TLV
Active_ID = A's MAC
Figure 27-2
Dual-active detected by A
As a remote switch, the Catalyst 4500 series switch supports stateful VSS client. In particular, the ID of
the current active virtual switch is synchronized from the active supervisor engine to the redundant
supervisor engine of the Catalyst 4500 series switch. This ensures that dual-active detection is not
disrupted even when the active supervisor engine switches over to the redundant supervisor engine.
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
27-22
Enhanced PAgP in VSS Normal Operation
Virtual
Switch A
(active)
EtherChannel
Remote switch TLV
Active_ID = A's MAC
Remote switch
(Catalyst 4500 series switch)
Active_ID = A's MAC
Enhanced PAgP in VSS Dual-active Scenario
Virtual
Switch A
(active)
Remote switch TLV
Active_ID = B's MAC
(Catalyst 4500 series switch)
Active_ID = B's MAC
Chapter 27 Configuring EtherChannel and Link State Tracking
Virtual
Switch B
VSL
(standby)
Virtual switch TLV
Active_ID = A's MAC
Remote switch TLV
Active_ID = A's MAC
VSL
EtherChannel
Remote switch TLV
Active_ID = B's MAC
Remote switch
Virtual
Switch B
(standby)
Virtual switch TLV
Active_ID = B's MAC