Port Trunking Across Multiple Swicthes

[ChrisMiles]

Hi Guys,

 

I am wondering if anyone knows if it's possible using ProCurve switches (3500yl-48Gs to be specific) to split one end of a trunk across two switches, for redundancy's sake. So for example, you'd have an 8 port trunk set up on one switch with 4 ports each going to two other switches with 4 port trunks configured.

 

I've done a lot of googling on the topic and the HP documentation doesn't seem to mention this scenario at all so I'm not hopeful but if anyone knows...

 

Thanks.

[teejay]

You need to use Spanning Tree Protocol for this, although it won't give you all 8 ports trunked, it would be 4 plus a redundant 4.

[PotNoodleTech]

Exactly as teejay says. You can set it up but you won't be able to use all 8 ports at once, you'll have the link to one of the switches 4 ports busy and the other switches 4 ports spare waiting for a failover.

[SYNACK]

Yeap, link aggregation for two seporate four link bundles along with STP to shutdown one of them so as to prevent a horrific loopback. If you want load balancing across them you are going to need smarter switches and different subnets along with a rather complex routing protocol.

[teejay]

Oh yes, forgot to say this is one of those holiday jobs, setting up STP redundant links is a very quick way to break your network:p

[ChrisMiles]

Ok guys, thanks

 

I'll have to look into whether or not we can live with only 4 ports, although I guess there is no reason why I couldn't set up two separate 8 port trunks in this case, if one is going to be disabled by spanning tree anyway but it would mean putting in additional cabling.