Can - one trunk the Fault Tolerant VLAN used by CSM.

[astanislaus]

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/mod_icn/csm/csm_4_2/config/wp1037240

We were pointed to the above document saying that the FT VLAN used by two CSM for redundancy cannot be trunked between the TWO CAT 6500 that the TWO CSMs are installed in. This is like saying the two CAT6500 cannot be in two different sites and must be near each other, because intersite links are generally trunk links carrying multiple VLANs including the FT VLAN used by the two CSMs in the two sites. Three of our customers are doing this and we want to be sure before telling them that they cannot trunk the FT VLAN.

[Gilles Dufour]

technically you can do it.

However this is not recommended.

If your trunk link gets overloaded with data, you may lose or delay CSM FT heartbeat and get failover or worst, 2 CSM active at the same time.

It is even worst if you are doing connection replication as this requires a good amount of bandwidth already.

Regards,

Gilles.

[astanislaus]

Thanks Gilles. We have to inform 3 of our customers who are already implementing FT VLAN through trunk link. They don't know that this cannot be done.