lag between stack unit on sge2010

[marcin.pudysz]

Can I create lag betwen stack unit to increase speed between units ?? stack connection is only 1Gbit on ports 24/48

if posible lag link must be in trunk mode ??

thank you for replay

[Tom Watts]

No, the stack ports are not "valid interfaces" when the switch is configured as a stack. Those ports are not configurable nor able to be viewed on the UI of the switch.

[marcin.pudysz]

Thanks for the reply. I do not want to aggregate ports for the stack. Stack wants to use to manage only. I need to increase the speed between the same vlan on different switchach . Can I use the stack and the lag. Or did i must destroy stack and configure stand alone units ?

[Tom Watts]

No, the spanning-tree will put the second lag in to a blocking status.

Example:

Stack unit 1 = Lag 1 using gi2/3

Stack unit 2 = Lag 2 using gi2/3

When you create the LAGS, you will notice you can choose the stack ID to associate the port to the LAGS. If you use LAG1 from unit 1, the ports will transpose to the unit 2 LAG1. That's why the LAG ID can't be the same.

If you look at the spanning-tree interface then hit the radio button for LAG you will see LAG 1 will be forwarding, LAG 2 will be blocking.

You have to view a stack as 1 whole device. It is the equivalance of having 1 switch and running 1 wire from port  1 to port 2, it will get shut down.

[marcin.pudysz]

I thought so, but I wanted to make sure. So if I want to increase the bandwidth between switches, I have to give up the stack, and configure switches separately. Thank you for your help.