Trunk Load Balancing across (2) 6509 switches.

[Skine]

I would like some opinions on load balancing across 2 6509 switches using trunk ports.

Here is the scenerio...

1 switch at the access layer, 2 switches and the distribution layer. The access layer switch has a GIG trunk link to each of the 2 dist layer switches. How would I implement equal-cost load balancing in a round robin fashion from the access layer switch to each of the 2 dist layer switches.

I would like to do this on a packet by packet level. CCO has some good tips, but only for load balancing from 1 switch to 1 switch, not 1 switch to 2 switches.

Any advice and help would be greatly appreciated.

 

[Farmer]

skine,

The best you could do is load balance per VLAN. In short, you'll use the "set spantree portvlanpri" command to accomplish this. Assign roughly 1/2 of the VLANs to one uplink and the other 1/2 to the other link. It won't get you packet by packet, but it should do the trick.

John Kowalski
john.kowalski@eds.com

 

[cpc]

skine,
I agree with john,and here is another approach you might want to look at.

1. Make one of the 6509s the root for vlans A,B,C and
secondary root for vlans D,E,F.

command: set spantree root A,B,C
set spantree root secondary D,E,F

2. Make the other 6509s the root for vlans D,E,F and
secondary root for vlans A,B,C.

command: set spantree root D,E,F
set spantree root secondary A,B,C

This will load balance vlan traffic but, it will not round robin the traffic between uplinks.