EdgeRouter - Virtual Private LAN Service (VPLS) with LDP Signaling


Overview


Readers will learn how to configure VPLS (Virtual Private LAN Service) using Label Distribution Protocol (LDP) for signaling.

NOTES & REQUIREMENTS:
Applicable to the latest EdgeOS firmware on all EdgeRouter models. Knowledge of the Command Line Interface (CLI) and advanced networking knowledge is required. Please see the Related Articles below for more information.
 
Devices used in this article:

Table of Contents


  1. Virtual Private LAN Service (VPLS) Overview and Prerequisites
  2. Setting up VPLS and LDP
  3. Verification and MAC Address Learning
  4. Related Articles

Virtual Private LAN Service (VPLS) Overview and Prerequisites


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Virtual Private LAN Service (VPLS) allows multiple sites to be connected and behave like a single Layer-2 domain. This is done by extending the LAN between sites using two VPLS endpoints, the PE (Provider Edge) routers in this example. Consider the following topology:

topology.png

VPLS topology using two PE routers (PE-1 and PE-2), extending the LAN between Site 1 and Site 2 to allow the clients in both 192.168.1.0/24 networks to communicate with each other.


This article will focus mainly on the VPLS and LDP configuration and assumes the PE routers are able to communicate with each other. The assumption is also made that there are one or several P (Provider) routers present in the internal network. In the example, the L2 tunnel is set up between two VPLS endpoints (the loopback interfaces). Providing reachability between PE-1 and PE-2 and the loopback addresses can be done by using OSPF for example.

Follow the steps below to modify the MTU settings on both PE routers and advertise the loopbacks into OSPF:

CLI: Access the Command Line Interface on PE-1. You can do this using the CLI button in the Web UI or by using a program such as PuTTY.

1. Enter configuration mode.

configure

2. Modify the MTU on the customer-facing interface.

set interfaces ethernet eth1 mtu 1504

3. Modify the MTU on the provider-facing interface and assign it an IP address.

set interfaces ethernet eth0 address 10.0.0.1/24
set interfaces ethernet eth0 mtu 1526
NOTE: The MTU on the customer-facing interface is increased to 1504, and 1526 on the provider side. This is to accommodate for LAN traffic that is tagged with a VLAN.

4. Assign an IP address to the loopback interface.

set interfaces loopback lo address 10.255.12.1/32

5. Enable the OSPF routing process on the relevant interfaces and define the OSPF area number.

set protocols ospf area 0.0.0.0 network 10.0.0.0/24
set protocols ospf area 0.0.0.0 network 10.255.12.1/32
NOTE: There is more information about configuring OSPF in the OSPF Routing article.

6. Commit the changes and save the configuration.

commit ; save

CLI: Access the Command Line Interface on PE-2.

1. Enter configuration mode.

configure

2. Modify the MTU on the customer-facing interface.

set interfaces ethernet eth1 mtu 1504

3. Modify the MTU on the provider-facing interface and assign it an IP address.

set interfaces ethernet eth0 address 10.0.0.2/24
set interfaces ethernet eth0 mtu 1526

4. Assign an IP address to the loopback interface.

set interfaces loopback lo address 10.255.12.2/32

5. Enable the OSPF routing process on the relevant interfaces and define the OSPF area number.

set protocols ospf area 0.0.0.0 network 10.0.0.0/24
set protocols ospf area 0.0.0.0 network 10.255.12.2/32

6. Commit the changes and save the configuration.

commit ; save
ATTENTION: The P router(s) will also need to be configured with an increased MTU (1526) and for OSPF routing.

Setting up VPLS and LDP


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VPLS and LDP can be configured next after achieving basic reachability between the loopback IP addresses. Besides the PE routers, LDP will also need to be enabled on the P routers. The same is not true for VPLS, which only needs to be configured on the tunnel endpoints (PE routers).

Follow the steps below to configure both VPLS and LDP on both PE routers:

CLI: Access the Command Line Interface on PE-1.

1. Enter configuration mode.

configure

2. Enable LDP on the provider-facing interface.

set protocols mpls interface eth0 label-switching
set protocols ldp interface eth0 enable ipv4
ATTENTION: LDP will also need to be enabled on the P router(s).

3. Define the VPLS instance ID and specify the remote tunnel endpoint address (loopback).

set protocols vpls instance vpls1 id 1 signaling ldp vpls-peer 10.255.12.2

4. Enable the VPLS instance on the customer-facing interface.

set protocols vpls interface eth1 instance vpls1

5. Commit the changes and save the configuration.

commit ; save

CLI: Access the Command Line Interface on PE-2.

1. Enter configuration mode.

configure

2. Enable LDP on the provider-facing interface.

set protocols mpls interface eth0 label-switching
set protocols ldp interface eth0 enable ipv4

3. Define the VPLS instance ID and specify the remote tunnel endpoint address (loopback).

set protocols vpls instance vpls1 id 1 signaling ldp vpls-peer 10.255.12.1

4. Enable the VPLS instance on the customer-facing interface.

set protocols vpls interface eth1 instance vpls1

5. Commit the changes and save the configuration.

commit ; save

Verification and MAC Address Learning


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Use the commands below to verify the reachability through OSPF and the operational status of LDP and VPLS:

show ip route ospf
show ldp session
show mpls forwarding-table

The command below can be used to view the learned MAC addresses on the customer-facing interface:

show vpls vpls1 mac-address

Related Articles


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EdgeRouter - OpenVPN Layer 2 Tunnel

EdgeRouter - EoGRE Layer 2 Tunnel

Intro to Networking - How to Establish a Connection Using SSH


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