Link aggregating HP and CISCO switch

[micro_xii]

I have cisco 2950 switch and configure as lacp ports 17-18 as group1 and ports 19-20 as group2 with Load Balancing. And all ports belong to VLAN1.

My goal is to link aggregate both HP procurve 2626 with cisco 2950.

My concern is my config in my HP.

procurve(config)#trunk e 21-22 trk1 lacp
procurve(config)#trunk e 23-24 trk2 lacp

I dont know if this is enough. What I want is to configure port 21-22 as lacp belongs to group1 and ports 23-24 as lacp belongs group2. Lastly,With LOAD BALANCING configuration added. Also belong to VLAN1

Pls, anyone can help me.

[Jeff Carrell]

i don't know how the load balancing feature works on the cisco...

your config on the procurve switch is ok as far as the lacp definition is concerned...

after creating the lacp group, you simply 'tag' or 'untag' the new interface(s) 'trkX' into vlan1 (or other vlans as required)...

however, there is no "load balancing" feature on the procurve switch, as the lacp standard as defined does its own load balancing over the multiple links in a group...

as i see it, if you connect the 2 lacp groups of the cisco to the corresponding 2 lacp groups of the procurve, you'll end up with a spanning-tree loop, and 1 of the lacp groups will go into blocking state, leaving you with only a 2 port lacp link...

seems to me that it would be better to make a single 4 port lacp group, and then you'll have the load balancing automatically...and less config...

hth...jeff

[micro_xii]

Hello;

You said if I connect like this: this will create loop....

cisco ports 17-18 --- procurve ports 21-22
cisco ports 19-20 --- procurve ports 23-24

Why do think this will create loop.In fact in procurve they are configuread as trk1 and trk2. Same goes to cisco as channel-group 1 and 2.

And you suggest: I will only create 1 group like this..will lacp configured.

cisco ports 17-20 ---- procurve ports 21-24

In your suggestion,I believe these are a waste of ports. Thats why I configure it 2 groups in cisco and procurve

[Jeff Carrell]

on the procurve sw:

lacp group 1 is its own interface made up of 2 ports, and that interface is now known as trk1...

lacp group 2 is its own interface made up of 2 ports, and that interface is now known as trk2...

when you create lacp groups, those new interface definitions will automatically be untagged in vlan1...the individual ports will actually be removed from all vlans they were defined in (untag or tag) at that point...the individual ports lose their individual definition as they are now part of a trk"x" interface definition...


when you connect these to interfaces (trk1 & trk2) between the 2 switches, and they are in the same vlan(s), you get a loop...its just as if you connected two single ports (not in a truck/lacp config) between the 2 switches...

if what you are wanting to accomplish is at least a 2 port link that will do load balancing and provide a larger path between the 2 switches, then you can simply configure a single 2-port lacp group on each switch, then you connect the switches together on those ports...

again, the lacp protocol/definition provides for load balancing without any other separate configuration required...it just does it...its based on dest mac addr from each switch's viewpoint...

hth...jeff