Pseudowire internet access design

[Artem Mitskiy]

Hello everyone,

I'm quite new to mpls so I ask for some guidance from more experienced community members.

I'm configuring devices for a small SP, aiming at delivering L2/3VPN for customers, using MPLS.

Network consists of three routers:

R1, loopback 1.1.1.1, it is an eBGP router, used as internet gateway for a network

R2, loopback 1.1.1.2, it is a 7600 PE device

R3, loopback 1.1.1.3, it is a 7201 PE device with a customer C1.

All connected to same MPLS cloud so each router has other two as LDP neighbors. There is no TE.

Problem:

C1 need to recieve internet access via R1.

Concept of current solution:

There is a tunnel xconnect mpls tunnel between R3 and R2 for customer traffic, wich is then trahsferred to R1 via dot1Q subinterfaces between R2 and R1.

More in-depth description at the end of this post

Desired solution

R2 seems like really unnecessary node here. Ultimately it just strips and slaps on MPLS tag. I'd like to terminate xconnect tunnel on R1 directly so it strips MPLS tag and then taking routing decision or vice versa.

Is it possible? If it is, can anyone provide me with config or docs on that scenario?

So far i've tried to create unnumbered interface on R1 and terminate xconnect here, but with no success.

Current solution:

C1 connected to subinterface in R1

interface G0/0.100

encapsulation dot1Q 100

xconnect 1.1.1.2 100 encapsulation mpls

Tunnel terminated on R2 on similar subinterface, but now phy interface directed at R1

interface G4/1.100

encapsulation dot1Q 100

xconnect 1.1.1.3 100 encapsulation mpls

And then traffic forwarded to R1 using simple VLAN connectivity and recieved on subinterface

interface G1/1.100

encapsulation dot1Q 100

ip unnumbered <Gateway_Interface>

service-policy Customer input

service-policy Customer output

[sreenivasgajula]

Look at using Integrated Routing & Bridging (IRB) or routed VPLS.

You can create a bridge-domain on R1 with a PW connecting R3, and a bridge-domain interface (BDI).

[Leonir Hoxha]

From what I see this can be accomplished in a simple way. You have 2 solutions here:

1) Terminate the Pseudowire on Internet Router (R1) on a BVI interface (Bridge-Domain is needed).

2) Terminate the Pseudowire on Internet Router (R1) via a Pseudowire Head-end interface (Bridge-Domain is needed).

Both solutions give you the flexibility of pure L3 routing at R1.

There are pros and cons whether you go with BVI or PW-HE, mainly on feature support and some limitations.