Re: Help! Need MPLS ce config example

itburnout · ‎10-13-2006

Hello all! Hope everyone is having an awesome friday.

We currently have a 3Mb frame connection feeding 9 remote sites via T1 point-to-point frame links. Sprint is moving us to MPLS, but i can't find any config examples on how to convert from frame to MPLS. Everything I seem to find is PE or otherwise.

We are running EIGRP internally with a backup PVC from each of the remotes to a backup site.

I have heard MPLS is easy to set up but I haven't had any luck finding info on how to set up an MPLS wan with eigrp.

Thanks for your help!

vladrac-ccna · ‎10-13-2006

A good start:

http://www.cisco.com/en/US/tech/tk436/tk428/tech_configuration_examples_list.html

Vlad

wochanda · ‎10-13-2006

As a CE router, there isn't much you have to do.

From your perspective, you're going to have a single PVC that you're going to use to reach all of your remote sites, so you just need to define the PVC, maybe apply some shaping, and turn up EIGRP on it.

Let your provider worry about the rest.

itburnout · ‎10-13-2006

Thanks for your quick response!

I know I'm making this harder than it really is. So exactly what do we do with the point to point pvc's on our routers that exist now under frame?

How do you define a pvc on mpls? See part of the reason we are scratching our heads on this is sprint has told us we pretty much just need to eliminate frame enacp on our interfaces and use HDLC. But that makes no sense whatsoever because I know that there has to be more to it than that.

Anyways, so we have 2 Frame T1's in a MFR bundle at our main site with PVC's to each remote. The remotes have 2 pvc's, 1 to our main site and 1 to our backup. We are running eigrp inside to keep everything happy in the event of a t1 faulre.

Am I making any sense? I think I just confused myself!

Thanks again!!

wochanda · ‎10-13-2006

Alright man..calm down.

When you migrate to MPLS, essentially all of the PVCs you used to have are routed over a single PVC. That being said, the provider can drop it off any way they want, such as:

Frame relay (single PVC)

ATM (single PVC)

HDLC

PPP (or multilink)

This choice is mainly based on the easiest way for them to get the data out to you at the speed you want.

How do you define a PVC on MPLS? You dont. Picture a connection to the public internet. You dont need to worry about how to get to all the destinations, you let your provider worry about it. In the case of MPLS, you just connect to your provider, and they worry about making sure all of your other sites are reachable through your link to them.

The only thing that may get complicated is the routing protocol you run with your provider. Most of the time you'll run BGP with them, but you can even use OSPF or EIGRP to connect to them. Basically you'll advertise your network out to the provider, they'll forward the updates to your spoke sites, and they'll know where to send the traffic to. In turn, the advertisements from your spokes will all come into your main site, and you'll know which networks are reachable via MPLS.

You may have seen MPLS configs around CCO, with VRF's and "tag-switching ip", but thats all your providers stuff. They put all that stuff in so that you dont have to worry about it.

So in a realistic scenario, lets say you order a 3mb connection to the MPLS cloud for your central site. They'll either provision a 2-T1 MFR bundle with a single PVC, or a MLPPP bundle with 2 T1's. Your config will look like this:

interface multilink1

ip address 257.24.1.2 255.255.255.252

router bgp 65101

neighbor 257.24.1.1 remote-as 65100

network 10.10.257.0 mask 255.255.255.0

You peer over your Multilink connection, and advertise the 10.10.257.0 subnet to your fellow MPLS routers, and the provider takes care of the rest.

As for your old frame network, leave it alone. Just make sure the MPLS routes are preferred.

Hope this helps,

Will

itburnout · ‎10-14-2006

HAHA Thanks for the advice *takes valium*

OK, I knew I was making it alot harder than it actually was. Sprint has given us practically no information. Basically they have said "ok, we have the circtuis provisioned, just let us know when you are ready to switch/test."

Just 1 quick question: The point to point subnets will go away. Will they still be maintained in some fashion, but instead be set up with the provider in some way? we had to send sprint a list of all our subnets including the p2p ones. I can only assume that it was so they could set up their routes and p2p subnets to peer with ours.

Thanks for your help!!

wochanda · ‎10-14-2006

Your CE router will be connected to a provider PE router which is running MPLS. Within this PE router, they have a VRF configured for you, which is essentially a routing table for only your routes. MPLS tags are then built based on the information in the routing table for your VRF.

All packets you send are going to first go to your gateway (the PE router). Once they get there, the PE router will do a lookup and determine which MPLS-VPN it is going to ride on. Then it will send it to the opposite-side MPLS PE router, who will convert it back to IP, and pass it to your spoke.

If they asked for a list of your routes, it may be because instead of passing along your routing protocol updates, they will be using static routes to route your traffic.