Figure 74: SONET/SDH-Based Layer 2 Circuit Topology Diagram

In this second Layer 2 circuit example shown in Figure 74, you configure a Layer 2 circuit for a SONET/SDH interface encapsulated with PPP.
On Router CE1, configure the SONET/SDH interface to handle PPP traffic. Be sure to use the same IP address prefix both here and on the SONET/SDH interface of Router CE2.
Router CE1
- [edit]
- interfaces {
-
- so-0/0/1 {
- description "to PE1 so-0/0/0";
-
encapsulation ppp;
-
- unit 0 {
-
- family inet {
- address 10.1.1.1/30;
- }
- }
- }
- }
On Router PE1, configure the PPP-based CE-facing interface with PPP CCC encapsulation. Establish your Layer 2 circuit with configuration of the l2circuit statement at the [edit protocols] hierarchy level. Remember to include in your Layer 2 circuit configuration the IP address of your remote PE neighbor (usually the loopback address of the neighbor), the interface connected to the CE router, and a virtual circuit identifier for this VC. Then, configure MPLS, LDP, and an IGP (such as OSPF) to enable signaling for your Layer 2 circuit.
Router PE1
- [edit]
- interfaces {
-
- so-0/0/0 {
- description "to CE1 so-0/0/1";
-
encapsulation ppp-ccc; # Configure CCC encapsulation on CE-facing interfaces.
- unit 0;
- }
-
- so-0/1/0 {
- description "to P0 so-0/0/0";
-
- unit 0 {
-
- family inet {
- address 192.168.245.22/30;
- }
-
family mpls; # Include the MPLS
family on core-facing interfaces.
- }
- }
-
- lo0 {
-
- unit 0 {
-
- family inet {
- address 10.255.145.126/32;
- }
- }
- }
- }
- protocols {
-
-
ospf {
- traffic-engineering;
-
- area 0.0.0.0 {
- interface so-0/1/0.0;
- interface lo0.0;
- }
- }
-
-
ldp { # LDP is required as the
signaling protocol for Layer 2 circuits.
- interface so-0/1/0.0;
- interface lo0.0;
- }
-
-
l2circuit {
-
-
neighbor 10.255.145.130 { #
This points to the loopback of the PE neighbor.
-
-
interface so-0/0/0.0 { # Here
you include the local CE-facing interface.
-
virtual-circuit-id 1; # Be sure
this ID matches the ID of your PE neighbor.
- }
- }
- }
- }
On Router P0, configure LDP, MPLS, and OSPF on the interfaces connected to the PE routers. The core router provides the MPLS backbone needed to tunnel Layer 2 traffic from the ingress PR router to the egress PE router.
Router P0
- [edit]
- interfaces {
-
- so-0/0/0 {
- description "to PE1 so-0/1/0";
-
- unit 0 {
-
- family inet {
- address 192.168.245.21/30;
- }
-
family mpls; # Include the MPLS
family on core interfaces.
- }
- }
-
- so-0/2/1 {
- description "to PE2 so-1/1/0";
-
- unit 0 {
-
- family inet {
- address 192.168.245.17/30;
- }
-
family mpls; # Include the MPLS
family on core interfaces.
- }
- }
-
- lo0 {
-
- unit 0 {
-
- family inet {
- address 10.255.145.129/32;
- }
- }
- }
- }
- protocols {
-
-
ospf {
- traffic-engineering;
-
- area 0.0.0.0 {
- interface so-0/0/0.0;
- interface so-0/2/1.0;
- }
- }
-
-
ldp { # LDP is required as the
signaling protocol for Layer 2 circuits.
- interface so-0/0/0.0;
- interface so-0/2/1.0;
- }
- }
On Router PE2, complete the Layer 2 circuit by configuring statements to match those previously set on Router PE1. Configure the PPP-based CE-facing interface with PPP CCC encapsulation. Complete your Layer 2 circuit with configuration of the l2circuit statement at the [edit protocols] hierarchy level. Remember to include in your Layer 2 circuit configuration the IP address of your remote PE neighbor (Router PE1), the interface connected to the CE router, and a virtual circuit identifier for this VC. Then, configure MPLS, LDP, and an IGP (such as OSPF) to enable signaling for your Layer 2 circuit.
Router PE2
- [edit]
- interfaces {
-
- so-1/0/0 {
- description "to CE1 so-1/0/1";
-
encapsulation ppp-ccc; # Configure CCC encapsulation on CE-facing interfaces.
- unit 0;
- }
-
- so-1/1/0 {
- description "to P0 so-0/2/1";
-
- unit 0 {
-
- family inet {
- address 192.168.245.18/30;
- }
- family mpls; # Include the MPLS family on core-facing interfaces.
- }
- }
-
- lo0 {
-
- unit 0 {
-
- family inet {
- address 10.255.145.130/32;
- }
- }
- }
- }
- protocols {
-
-
ospf {
- traffic-engineering;
-
- area 0.0.0.0 {
- interface so-1/1/0.0;
- interface lo0.0;
- }
- }
-
-
ldp { # LDP is required as the
signaling protocol for Layer 2 circuits.
- interface so-1/1/0.0;
- interface lo0.0;
- }
-
-
l2circuit {
-
-
neighbor 10.255.145.126 { #
This points to the loopback of the PE neighbor.
-
-
interface so-1/0/0.0 { # Here
you include the local CE-facing interface.
-
virtual-circuit-id 1; # Be sure
this ID matches the ID of your PE neighbor.
- }
- }
- }
- }
On Router CE2, configure the SONET/SDH interface to handle PPP traffic. Be sure to use the same IP address prefix both here and on the SONET/SDH interface of Router CE1.
Router CE2
- [edit]
- interfaces {
-
- so-1/0/1 {
- description "to PE2 so-1/0/0";
-
encapsulation ppp;
-
- unit 0 {
-
- family inet {
- address 10.1.1.2/30;
- }
- }
- }
- }