Re: 3560 redundant links

charlie.restivo · ‎01-24-2007

We recently installed 2 3560's with one FSO link on Gi0/1 on both switchs and an RF 5.8GHz link on Fa0/1. Gi0/2 goes to his netwrok on both sides. I configured the switches using smartport in the gui. The FSO's are connected and running fine, however as soon I plug in the RF 5.8 link for redundancy after about 30 seconds to a minute my throughput drops completely. If I unplug or do a shut on the Fa0/1 port it comes right back up. One thing i hope is not an issue is the fact the customr has a flat network. It wasn't made known to me until recently so I'm not sure if what he wants to do can be done on a none routed network. I was hoping to just use STP to control the fail over. I've included the configs on both 3560's and a map of the wireless links with IP's

e-dennington · ‎01-24-2007

Sounds like spanning tree isn't putting one of the ports into blocking and I would have to wonder if it has to do with the wireless link. Can you do a "sh spann vlan1" and see what the state of the ports are with all interfaces up? one port on one of the switches should be blocking since it is all the same vlan across both switches and you have dual connections between them.

charlie.restivo · ‎01-26-2007

we got the same results. Niether of the Fa0/1's would go into blocking mode.

charlie.restivo · ‎01-30-2007

we got the same results. Niether of the Fa0/1's would go into blocking mode.

HansPauly · ‎01-30-2007

Based on the diagram, this should work.

I would suggest that STP is favoring the RF links. What's not know is where the STP root is.

I'd tear down / diaable the RF and carefully map out the STP costs, etc. Re-enable the RF, and again check out the STP topology, If you this proves that the RF link causes on the the Gig2 interface to block, you should be able to get around that by setting port costs.

I pressume this is a Layer-2 conection.

charlie.restivo · ‎01-30-2007

Yes, this is a flat network. Not how I would do it but the customer has had it this way for a while and cant change because of the size. When we tried enabling all the ports we found that none of the RF ports (Fa0/1 on both switches) neither went into blocking. The STP port costs are default, should I try changing them, if so what do you suggest?

HansPauly · ‎01-30-2007

I was thinking about this ...

I suspect that BPDU's are NOT getting across the GIG links...

charlie.restivo · ‎01-30-2007

What would suggest I look for and/or change?