VSS for access switch

[eit-homing]

I've been told before that when a supervisor card goes down in one of the VSS chassis, the line cards on the same chassis will also go down.  Is that true?  So if I have server directly connect to the line card in that chassis, they will be impacted if the supervisor card go can.  If this is true, then VSS is not intended for access switches unless all your servers will dual home to both vss switches.  Can someone give me more detail on this?  Thanks.

[Reza Sharifi]

Correct, VSS is not intended as an access switch, however it can be used in data center environments where you can connect multiple NICs to multiple 6500s (VSS) using etherchannel.

It is also true that if you loose the sup, the entire box will go down and all the line cards go with it too.

currently, you can deploy 2 sup per 6500 using IOS SXI4 or later, but if the first sup goes down the box will reboot.  So essentially quad sup per vss set does not provide any benefit.  In the next few month with the newer IOS version you are able to put 2 sups in each 6500 and in case of the first sup fails, the second sup will take over the responsibility, but Cisco is not there yet.

HTH

Reza

[vmilanov]

Yes, it is true. If a chassis has a single supervisor and it fails, then chassis would become bare metal util the sup has been recovered. The fabric, VSL links, etc will go down and the line cards, nor any other module, do not have the ability to process traffic entirely by them selves.

In this case, a redundant supervisor in each chassis will overcome this issue.

HTH/Regards,

Vasil