VLAN's and spanning tree question

anthonysgroi · ‎06-21-2007

Hi everyone, I have two 6509's acting as our cores doing all our routing with multiple vlans. And 4500 series access layer switches(2 uplinks). All with redundant 10Gig links, what i want to do is make is so that certain VLANS go out certain uplink ports, so effectively both interfaces on the access layer switches are passing "half" of the traffic. Do i accomplish this by settings different VLAN priorities on the cores for the VLANS? What do i need to do on the access layer? Any help is much appreciated.

Patrick Laidlaw · ‎06-21-2007

Hello,

I'm going to make a couple of assumptions. I'm Assuming the following

1.your 6509 cores are fully redundant for each other.

2.Each Core is running a first hop redundancy protocol (HSRP, GLBP, VRRP)

3. Sample vlans 10,20,30,40,50,60

For the above I would setup my spanning tree so that: core1 stp has priority 8192 for vlans 10 20 30 and priority 16384 vlans 40 50 60.

Core2 stp has priority 8192 for vlans 40 50 60 and priority 16384 for vlans 10 20 30.

For the First Hop redudancy protocol I would setup core1 with the higher priority for vlans 10 20 30 and Core to with the higher priority for vlans 30 40 50.

On the access layer just leave everything else as it is.

Patrick

farkascsgy · ‎06-22-2007

If you change the priority for one vlan it doesn't mean that the traffic will goes on different path.

Trick with HSRP can be a good load balancig solution.

Check MSTP:

http://www.cisco.com/warp/public/473/147.html

Bye

FCS

Please rate me if I helped.