Hi All, Trying to find an answer to a single technical point concerning a migration of a fleet of Catalyst 6500's to VSS-1440. I've had a scan through the documentation on CCO (whitepapers, config guides, migration guides, etc.) but cannot find anything dealing with this one specific point. Background: Assume that on both stand-alone chassis, you have a specific vlan interface with L3 configuration, such as: switch1: vlan 10 name testing ! interface vlan10 ip address 10.100.100.1 255.255.255.0 glbp 1 ip 10.100.100.254 glbp 1 preempt glbp 1 load-balancing round-robin ! switch2: vlan 10 name testing ! interface vlan10 ip address 10.100.100.2 255.255.255.0 glbp 1 ip 10.100.100.254 glbp 1 preempt glbp 1 load-balancing round-robin ! Once switch 1 is converted to VSS mode and is brought up as ACTIVE/MASTER, it will keep it's layer3 configuration on the VLAN interface. The question is what happens to the L3 configuration on switch2 when it comes up in STANDBY/SLAVE? I can foresee one of two possibilities, but not sure which to expect before trying to do this in a live enviroment: either: 1. switch2 will boot up straight into NSF/SSO, inheriting its [new L3] configuration from the active master, overwriting the pre-VSS L3 configuration. (would be preferable). or 2. switch2 will boot up and enter RPR mode with incompatible configuration for the interface, forcing me to have to manually remove the L3 configuration from the interface before I can proceed with the migration. (not really ideal with hundreds of vlans on these things...) Any idea which one of these would be the case ? (the glbp will be retained, as it will be running between two VSS pairs with 10G trunks between them). Thanks in advance Leland