MPLS Lab Setup
Introduction
This page is an attempt to put together a lab setup for the testing of MPLS / VPLS as well as Traffic Engineering. This is not an attempt to explain how MPLS works, rather it is to promote discussion around the operation of MPLS. Before working through this lab you should first familiarize yourself with the concepts in this WIKI article http://wiki.mikrotik.com/wiki/MPLSVPLS as most of the setup has been based around those concepts. As my understanding of MPLS is also rather limited please feel free to edit and correct where required. If you want the original network diagram (in Visio format) please email me on david [at] mikrotiksa dot com. I can also export to some other formats. There is also a discussion on the forum about this wiki. Please check for updates.
Lab Setup
Network Diagram
First lets look at a network diagram of the basic setup File:MPLS Lab Setup.png
The setup was created using 6 RB532's, but anything with 3 network interfaces and 32MB memory should be able to do the job. P1 - P3 are the Provider (MPLS Backbone) routers. PE1 - PE3 are the Provider Edge routers which do the Label Popping
Router Setup
Loopback Interface
Each router is setup with a loopback adapter lobridge which holds the loopback address. From http://wiki.mikrotik.com/wiki/MPLSVPLS we can see this serves 2 purposes:
- as there is only one LDP session between any 2 routers, no matter how many links connect them, loopback IP address ensures that the LDP session is not affected by interface state or address changes
- use of loopback address as LDP transport address ensures proper penultimate hop popping behavior when multiple labels are attached to packet as in case of VPLS
Here is a typical router setup (this is from P1)
P1
/interface bridge add name=lobridge /ip address add address=10.255.255.1/32 interface=lobridge
The other routers are setup with 10.255.255.2-6 as per the diagram above
P2
/interface bridge add name=lobridge /ip address add address=10.255.255.2/32 interface=lobridge
P3
/interface bridge add name=lobridge /ip address add address=10.255.255.3/32 interface=lobridge
PE1
/interface bridge add name=lobridge /ip address add address=10.255.255.4/32 interface=lobridge
PE2
/interface bridge add name=lobridge /ip address add address=10.255.255.5/32 interface=lobridge
PE3
/interface bridge add name=lobridge /ip address add address=10.255.255.6/32 interface=lobridge
IP Addressing
We then setup the links between the core routers and the core-edge routers as per the diagram:
P1
/ip address add address=10.0.255.1/30 interface=ether1 add address=10.0.255.5/30 interface=ether2 add address=10.1.0.254/24 interface=ether3
P2
/ip address add address=10.0.255.6/30 interface=ether1 add address=10.0.255.9/30 interface=ether2 add address=10.2.0.254/24 interface=ether3
P3
/ip address add address=10.0.255.10/30 interface=ether1 add address=10.0.255.2/30 interface=ether2 add address=10.3.0.254/24 interface=ether3
PE1
/ip address add address=10.1.0.1/24 interface=ether1
PE2
/ip address add address=10.2.0.1/24 interface=ether1
PE3
/ip address add address=10.3.0.1/24 interface=ether1
Dynamic Routing Setup
Next we can setup OSPF on each router to dynamically distribute routes
P1
/routing ospf instance set distribute-default=never redistribute-connected=as-type-1 router-id=10.255.255.1 numbers=default /routing ospf network add area=backbone network=10.0.255.0/30 add area=backbone network=10.0.255.4/30 add area=backbone network=10.1.0.0/24
P2
/routing ospf instance set distribute-default=never redistribute-connected=as-type-1 router-id=10.255.255.2 numbers=default /routing ospf network add area=backbone network=10.0.255.8/30 add area=backbone network=10.0.255.4/30 add area=backbone network=10.2.0.0/24
P3
/routing ospf instance set distribute-default=never redistribute-connected=as-type-1 router-id=10.255.255.3 numbers=default /routing ospf network add area=backbone network=10.0.255.0/30 add area=backbone network=10.0.255.8/30 add area=backbone network=10.3.0.0/24
PE1
/routing ospf instance set distribute-default=never redistribute-connected=as-type-1 router-id=10.255.255.4 numbers=default /routing ospf network add area=backbone network=10.1.0.0/24
PE2
/routing ospf instance set distribute-default=never redistribute-connected=as-type-1 router-id=10.255.255.5 numbers=default /routing ospf network add area=backbone network=10.2.0.0/24
PE3
/routing ospf instance set distribute-default=never redistribute-connected=as-type-1 router-id=10.255.255.6 numbers=default /routing ospf network add area=backbone network=10.3.0.0/24
You should now have a working OSPF routed system
MPLS Setup
The next step is to add and configure the MPLS system. In order to distribute labels for routes, LDP needs to be enabled. Then all interfaces that participate in MPLS need to be added.
P1
/mpls ldp set enabled=yes lsr-id=10.255.255.1 transport-address=10.255.255.1 /mpls ldp interface add interface=ether1 add interface=ether2 add interface=ether3
P2
/mpls ldp set enabled=yes lsr-id=10.255.255.2 transport-address=10.255.255.2 /mpls ldp interface add interface=ether1 add interface=ether2 add interface=ether3
P3
/mpls ldp set enabled=yes lsr-id=10.255.255.3 transport-address=10.255.255.3 /mpls ldp interface add interface=ether1 add interface=ether2 add interface=ether3
PE1
/mpls ldp set enabled=yes lsr-id=10.255.255.4 transport-address=10.255.255.4 /mpls ldp interface add interface=ether1
PE2
/mpls ldp set enabled=yes lsr-id=10.255.255.5 transport-address=10.255.255.5 /mpls ldp interface add interface=ether1
PE3
/mpls ldp set enabled=yes lsr-id=10.255.255.6 transport-address=10.255.255.6 /mpls ldp interface add interface=ether1
This should now give you an operational MPLS setup.
