Cisco 6500 VSS
NSF (Non Stop Forwarding)
SSO (Stateful Switch Over)
EFSU (Enhanced Fast Software Upgrade)
Upgrade the IOS version without any downtime.
Virtual Switch domain (Step 1)
Virtual Switch link (Step 2)
Conversion (Step 3)
grouping the two switches using an ID
used to exchange configuration and stateful information between the two physical switches
Single Physical Link or Etherchannel
Adds a Virtual switch Header to each frame sent on the link
The configurations of both switches will be merged into a single configuration
The interface numbers will be renumbered from slot/port to switch-number/slot/port.
Negotiation to determine which switch is active or standby.
SW-VSS#show switch virtual
SW-VSS#show switch virtual link
SW-VSS#show interfaces vsl
SW-VSS#show switch virtual role
make sure that there is no re-convergence for (routing) protocols.