0

This is probably more of a design question. I have two transit providers where I am receiving the full Internet routing table (via BGP) and am also participating in an IX where I am receiving routes from peers within that IX (also via BGP). I then redistribute those routes to the rest of my network through OSPF. I then have a core router which I have connected an end device.

Here's a diagram explaining it all:

All of the Edge devices and the Core router are running Vyatta 6.5. My end device is simply a Linux box that I can perform traceroutes from (to see where my traffic is going).

As you can see, I have different link speeds to my providers. Ideally, I'd prefer for pretty much all the traffic to go through ISP B where I have a 1Gbps connection, and only have ISP A's transit sitting there waiting for ISP. Likewise, if a network is available in the table through my connection to the IX, I would like to preference that network.

At the moment, all of my traffic is going through ISP A.

With Vyatta, how can I go about adding a 'weight' or some kind of preference value to say:

  1. If the network is available through Edge 3, go there
  2. Else if the network is available through Edge 2, go there
  3. Else, go through Edge 1

I hope my question is clear. If it's not or you want some output from any of these routers, please let me know. Thanks for your assistance :)

1 Answer 1

1

(Assuming that Vyatta supports BGP...) Why don't you use iBGP among Edge1, Edge2, Edge3 and Core routers instead of redistributing BGP to OSFP? Redistributiong full bgp routes to OSPF is highly discouraged because OSPF is not designed to handle such a large amount of routes.

If you use iBGP for distributing routes from your ISPs, then use local-preference to control your routes.

  1. set local-preference to 120 for routes receiving from Edge 3.
  2. set local-preference to 110 for routes receiving from Edge 2.
  3. leave local-preference untouched for routes receiving from Edge 1. (assuming default local-preference value is 100)

Within an AS, every iBGP router prefer route with higher local-preference. So if there are same routes from Edge 1, Edge 2 and Edge 3, routes from Edge 3 is prefered.

BTW, you can have better answer from Network Engineering for this kind of question.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .