truking port requirement

[airwolf09]

Can someone please tell me when trunking multiple ports either LACP/TRUNK do all the ports have to be on the same module or can i trunk port from different module on the same switch to get better throughput/load balance

which of the below should be the correct or recommend.

trunk a1, b1, c1,d1 trk1 TRUNK

or

trunk a1,a2,a3,a3 trk1 TRUNK

thanks,

[paulgear]

You can definitely trunk across modules.  I routinely do that for resilience purposes, to protect against possible line card failure.  What i usually do is pick a fixed port in each module (usually the first) and trunk from the same port on multiple modules.  I'm unconvinced this makes any difference from a performance perspective, but i'll leave that to those more qualified than myself to comment.

[Richard Litchfield]

I would nearly always use LACP instead of TRUNK. Do this at both ends to ensure an LACP (standards-based aggregation link).

Given the choice, I would also choose a1,b1,c1,d1, but so long as you have ports from more than one module, you have the resiliency in case one module has a problem.