[c-nsp] mpls and BGP question

netman netman at oneidatel.net
Mon Oct 22 21:16:27 EDT 2007


Hi,

I have the following situation I am trying to configure.

We have eight 7604 routers all connected point-to-point via 10 gig links

so something like this (10 gig network)

R1--R2--R3--R4--R5--R6--R7--R8

Hanging off of each router is a companies cisco or foundry router (CE). The 
current 10 gig network supports IPTV (multicast traffic) using private 
addresses. OSPF routing is configured on the 10 gig network

Right now there are multiple T1's coming from the CE's to the Internet 
Gateway. All routes are handled by static routes  (not my doing)

I need to move the intenet traffic off of the T1's and over to the 10 gig 
network.

I connected an interface on the Internet gateway router (IGW) to R5. I 
cannot use sub-interfaces on the connection between R5 and the IGW. In fact 
they do no want me messing with the configuration on the IGW.

R1--R2--R3--R4--R5--R6--R7--R8
                                |
                            IGW

I want to use MPLS to carry our Internet traffic from all 8 companies. I was 
thinking of one vrf for all eight companies)

I have been playing around with dynamips, since I cant experiment on a 
production network. I simulated what I wanted to do with only 5 routers 
(CE--PE1--PE2--PE3--IGW)

I was having problems getting the default route from PE3-IGW through BGP to 
PE1. It was showing up on PE2.

on CE I created a loopback interface of 2.2.2.2/24
on IGW I created a loopback interface of 1.1.1.1/24

on IGW I had a static route to 2.2.2.2 via the interface on PE3 facing the 
IGW.
on CE I had a default route pointing to the interface on PE1 connect to CE
on Pe1 I had ip route vrf INTERNET 2.2.2.2 255.255.255.0 to IP address of CE 
interface
on PE3 I had the default route ip route vrf INTERNET 0.0.0.0 0.0.0.0 
serial1/0 IGW's ip address

I could see the default route on PE2 when I did a sho ip route vrf INTERNET.

However I could not see it on PE1 issuing the same command.

Reading somewhere on the Internet I made PE1 and PE3 route reflector clients 
for PE2.

I now had the route at PE1 .
I turned on debug ip icmp on all routers

I did an extended ping on CE to IGW using the ip address to 1.1.1.1 (IGW 
loopback) and from 2.2.2.2 (CE loopback)

The debug on router IGW - showed it sent a reply src 1.1.1.1 dest  2.2.2.2
the debug on router CE - showed it received a reply from src 1.1.1.1 for 
dest 2.2.2.2

However the success rate on CE was 0 %. (even though the debug showed it 
received the reply)

So here is my question.

On the example above do I need to have a router reflector for  this to work?

If so, if PE5 was the RR, would I need to include all the other PE routers 
as clients?

Finally, is there an easier way to accomplish this task. All 8 companies 
share the costs of the 10 gig network and bandwdith to the Internet. So it 
is a privately owned network.

I was wanting to use MPLS for our Internet traffic, because in the future 
their might be other companies that use this network as a transit from one 
location to another. I would like to keep it seperate from our traffic.

I have no problems reading if someone were to have a nice link to send me. I 
have been working on this for too long and would like to knwo if I am on the 
right track or if there is a better way to implement a solution.

Thanks

Don Hickey




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