GLBP usage 1

[jimfixit]

I am working with an inherited set up. In the beginning there were 3 offices, connected with dark fiber, like so:

6513
/ \\
/ \\
4509 6509

There were 2 fiber runs port-channeled to the 6509 and 1 fiber to the 4509. The predecessor, instead of giving each office it's own vlan based on geography has end to end vlans all over the place on these 3 pieces of equipment.

Enter the next thing: customer puts another fiber between the 4509 and the 6509, for 'backup', basically completing the triangle. NOW of course they want to 'use it all the time, not just for backup'.

STP issues asside, which I'm reading up on now, without some fancy configurations I think that we could experience serious delays if a link comes or goes.

I'm also thinking my best hope for the load balancing/fail over is GLBP with some weighted values, but maybe not. I can't use a traditional routing protocol because the IP subnets are used in all three locations. While I wait to convince them we need to fix this, I still have this need to make use of this thousand dollar a month line they just put in....

ideas? Is GLBP a good way to accomplish this?

 

[burtsbees]

NOW of course they want to 'use it all the time, not just for backup'.
That is a port-channel config---STP remember will block all but one...

Burt

 

[VinceWhirlwind]

I think the only way to "use it all the time" would be to have all 3 switches routing - something you can't do because of your VLANs.

How about this? Upgrade the Sups on the 6500s and implement VSS between them. Then, configure an etherchannel from the VSS to the 4500.
Bingo - Layer 2, VLANs everywhere you want them, all 3 links "in use all the time", excellent redundancy.

 

[jimfixit]

vss...wow, let me go read on that... doubt they have money to update the sups but you never know....

 

[baddos]

As a cheap alternative, you could look at pvst and split up which vlan is blocked by stp on the two 4500 interfaces.

Say you have vlan 1,2,3 and 4.


gig1/1 vlan 1,2 weighted
gig1/2 vlan 3,4 weighted

 

[BuckWeet]

While we're at it, why not upgrade to the 7k's and use VPCs ??

LOL