VSS

[r.crist]

We are investigating VSS as a failover/load balancing solution. Does anyone have experience with Virtual Switching? Any input on if or how it operates with Sun and Microsoft servers? It looks like Sun supports link aggregation, which is based on the 802.3ad spec (as is Cisco's EtherChannel), but our Sun admins want to use IPMP, which apparently is a layer-3 protocol and isn't 802.3ad compliant. Anyone else out there using VSS yet? Thanks - Rich

[bilousand]

It's only important to avoid Active-Active state of VSS machine. In cisco-only configuration any MEC with extended PAgP will be used to propagate state of nodes to each other in case when VSL fails. In non-cisco environment the only solution is to use out-of-band link between VSS nodes with BFD configured. In case VSL link fails, the dual-active state will be detected and resolved according to the programmed rules (standby will become active and active will restart iirc). More about it here: http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps9336/prod_white_paper0900aecd806ee2ed_ps2797_Products_White_Paper.html