RIP Manual Load Balancing?

[philipeddies]

Hi,

I have three 3750 stacks, two at my production site in different buildings linked by fiber and one at our DR site.

Between the three stacks I have RIP v2 configured; we also have a few other sites connecting to our main site.

We replicate SAN data, VMware data, IBM iSeries data and a few others bits between servers in our main building at our production site and our DR site.

Obviously rip is pushing all of this data over the wan link between our main building and our DR site and our second link to our DR site is sitting there unused for the most part unless the primary link goes down.

This primary link is pretty maxed out so I am looking for some suggestions for how I can level up the bandwidth usage. As we are using rip and the two paths have unequal costs I know I can’t use rips built in load balancing.

Also times are tight and I have been told I can’t spend any money as much as I would love to be using eigrp ;-)

[Richard Strnad]

Hi Phil,

I think that it's not possible to give you an universal advice, but i would love to give you some inputs that you can find the best solution for your case.

Some more Informations would be good, is there HSRP between the production side? Is there some Traffic that flows HA/DR Site -> Mail Building -> Comms Rack ?

Maybe you could work with a Offset List?

Regards

Richard

[philipeddies]

Hi Richard,

Thanks for the reply,

There is no HSRP between on the production side.

There is no traffic that flows HA/DR -> Main Building -> Coms Rack, there is LAN traffic between the main building and the comms rack. Currently the only time there is any WAN traffic in or out of the comms rack it is when the primary line fails.

I have not worked with Offset Lists before, I have just done a quick google and they sound promising can you explain a little further how you would see this working?

Thanks

Phil

[Richard Strnad]

Hi Phil,

Thanks for the additional informations.

First you should try to find out the traffic patterns (traffic flow) in your network.

Site A:
Network 1

Network 2

Site B:

Network 3

Network 4

Maybe the traffic always goes from Network 1 to Network 3 and from network 2 to network 4 or something like that.

You can easy just offset one of the network but the chances are great that you then introduce asymmetric routing in your network. This can be a problem for some application, so you should really consider this point.

Regards

Richard

[philipeddies]

Hi Richard,

Thanks for that, I am going to go and have a play with offset lists on our test rack and do a bit of reading.

Thanks for your help

I will reply back later

[smitesh kharecha]

Hi Phil,

If I understood correctly, you want to load share across your 2 WAN links.

And obviously since your are using RIP ( Or even any other protocol for that matter) by default you will end up using one WAN link only based on your topology.

The Key to solve this problem is to make the metric same via both the paths.

In your case, you need to increase the RIP metric via direct path to match that of learned via unsed path (which I believe should be 2 hops).

You can use distribute-list offset-list for that matter.

Regards,

Smitesh Kharecha

PS: Please rate helpful posts.

Edit: Sorry it is not distribute-list but offset-list.

Message was edited by: smitesh kharecha

[smitesh kharecha]

Phil.

Two solution are as below:

Solution 1: Make standard access-list to match your routes at DR and then inside rip process apply the following command

offset-list out 1

Interface should be the WAN link which is currently used and getting maxed out.

Solution 2: Make standard access-list to match your routes at Main Building ( as per your snapshot) and then inside rip process apply the following command

offset-list in 1

Interface should be the WAN link which is currently used and getting maxed out

HTH,

Smitesh Kharecha

PS: Please rate helpful posts.

[philipeddies]

Hi,

It is sounding like offset lists should do the job, I will have a play on our test rack and report back.

Thanks for your help guys

Phil

[Vasilii Mikhailovskii]

Hi, Phil.

Is it possible to summarize networks per building/HA somehow?

If yes, you could build you load-balancing based on longer-match (like the following):

• HA advertize to building 1: 10.0.0.0/16 + 10.1.0.0/24 + 10.1.1.0/24 + etc.
• HA advertize to building 2: 10.1.0.0/16 + 10.0.0.0/24 + 10.0.1.0/24 + etc.