Hi Alok On a VSS you combine two switches to one control plane. This means you have one IP addresss for configuration. On a MLAG or vpc (cisco nexus) you have two switches and two management IP. So you have two control planes. On VSS you have a ISSU. But hitless update is not worki g on bigger firmware changes. So you have a downtime. On MLAG, you can uodate each switch indipendendly (witch exception to release nites) We use MLAG witch X670 and are very happy. If you use MLAG, make use of the Alternate Link. Regards Mucha
