Mpls : Simple Mpls Implementation Using Cisco® Two Routers/Switches (L3)

3. Simple MPLS implementation using two routers/switches (l3)

a. Using Cisco routers

The following example shows how to configure MPLS hop-by-hop forwarding on the interface. MPLS forwarding on Cisco routers requires that CEF be enabled. To enable CEF on a router, issue the following commands:

Router# configure terminal

Router(config)# ip cef [distributed]

configure MPLS hop-by-hop forwarding for a router interface by issuing the following commands:

Router# configure terminal

Router(config)# ip cef [distributed]

configure MPLS hop-by-hop forwarding for a router interface by issuing the following commands:

Router# configure terminal

Router(config)# interface s 0/0

Router(config-if)# mpls ip

mpls label protocol {ldp | tdp | both}

Example:

Router(config)# mpls label protocol ldp

Above command configures use of LDP on all interfaces.

On router use "show MPLS interface" to verify that the interfaces are configured to use LDP.

Router#show mpls interface

Interface              IP            Tunnel  

Ethernet3/0            Yes (ldp)     No               

Ethernet3/1            Yes           No

Example:

MPLS implementation using two Cisco routers

1. In this example network is configured with EIGRP as routing protocol.

2. Then run MPLS over the IP network to fast switch layer 2 interfaces

Configuration on Router R1

R1>enable

R1#conf term

R1(config)#int loopback 0

R1(config-if)#ip address 172.16.1.1 255.255.0.0

R1(config-if)#no shutdown

R1(config-if)#exit

R1(config)#int fastethernet 0/0

R1(config-if)#ip address 172.16.12.1 255.255.0.0

R1(config-if)#no shutdown

R1(config-if)#exit 

R1(config)#router eigrp 1

R1(config-router)#no auto-summary

R1(config-router)#network 172.16.0.0

R1(config-route)#exit

R1(config)#interface fastethernet 0/0

R1(config-if)#mpls ip

Configuration on Router R2

R2>enable

R2#conf term

R2(config)#int loopback 0

R2(config-if)#ip address 172.16.2.1 255.255.0.0

R2(config-if)#no shutdown

R2(config-if)#exit

R2(config)#int fastethernet 0/0

R2(config-if)#ip address 172.16.12.2 255.255.0.0

R2(config-if)#no shutdown

R2(config-if)#exit

R2(config)#int s 1/0

R2(config-if)#ip address 172.16.23.2 255.255.0.0

R2(config-if)#no shutdown

R2(config-if)#exit
 

R2(config)#router eigrp 1

R2(config-router)#no auto-summary

R2(config-router)#network 172.16.0.0

R2(config-route)#exit

R2(config)#interface fastethernet 0/0

R2(config-if)#mpls ip