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.