Craig

I'm not sure what you mean by 3 different backplane slots, as i am only aware of 2 ie.

1) the classic shared 32Gbps bus

2) The Crossbar switch fabric.

Some modules such as the 10GE modules have 2 connections on them but they are still both connecting into the crossbar fabric.

To answer your question. The Supervisor 720 must go in slot 5 and the redundant supervisor (if you have one) in slot 6. After that with the 6509E you can put your other modules in any available slot.

Some chassis do have limitations such as the 6513 where any module with dual connections, such as the 10GE modules, have to go in slot 9 - 13 because only these slots provide dual connections to the switch fabric. But there are no such limitations with the 6509E.

Jon