Stacked ProCurve switches

[cookie_monster]

I'd like to stack our two 2910al switched so that I can balance a four NIC link over two switches to protect my SAN traffic against a single switch faliure.

 

Anyone else using HP switches in a stacked config like this, if so what issues might I run into before I go chasing down this path?

 

Cheers.

[DMcCoy]

I'd like to stack our two 2910al switched so that I can balance a four NIC link over two switches to protect my SAN traffic against a single switch faliure.

 

Anyone else using HP switches in a stacked config like this, if so what issues might I run into before I go chasing down this path?

 

Cheers.

 

Issue 1 - You can't (if you are envisiaging the special connectors for other brands). You could have some on one switch an some on another, but you cannot get both switches to appear as a single entity except for managment purposes. See http://h20430.www2.hp.com/other/procurve/cn/zh/network/pdfs/ProCurve_Stacking_Technology.pdf for more details.

[pete]

You'll be looking at a pair of 3750s or something from Nortel/Juniper to achieve this in hardware.

 

You can do it via L3 routing and different subnets - see here: Virtual Geek: A Multivendor Post to help our mutual NFS customers using VMware - the diagram about 1/2 way down the page will explain the idea (direct link http://virtualgeek.typepad.com/.a/6a00e552e53bd28833011570e408f8970b-pi ).

 

There's a few useful bits of info about NFS as well, albeit a lot that's vmware-specific.

[budgester]

Sounds like you might be wating to do something with Trunking and STP.

[Geoff]

This'll work fine with what you have.

 

Create two trunk ports on each switch and trunk two of your nics into each switch. Enable STP and connect both switches together. If you did it right, one of your trunk ports should get blocked via STP.

 

With that out of the way, connect both your switches to your LAN. If you did your STP correct, one of the switches will get locked out via STP

 

(because of this, it's helpful if you have separate VLAN for management, so even if your 'data' VLAN gets locked out via STP you can still reach the switch via the management VLAN to admin it).

 

Now testing... In theory you should be able to pull power on either switch and the STP will reroute. You should be able to pull any patch cable and the STP should reroute.

 

Is that what you wanted?

[pete]

I got the impression he was after 4 nics passing traffic with failover to 2.

[cookie_monster]

Ok so you're saying that they don't need to be stacked I can just rely on STP to sort it? The problem is that then (if i'm with you) i'll have two bonds on different IP's rather than one 4 NIC bond providing all the throughput.