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Example: Interconnecting a Layer 2 VPN with a Layer 2 VPN

This example provides a step-by-step procedure for interconnecting and verifying a Layer 2 VPN with a Layer 2 VPN. It contains the following sections:

Requirements

This example uses the following hardware and software components:

  • Junos OS Release 9.3 or later
  • 2 MX Series 3D Universal Edge Routers
  • 2 M Series Multiservice Edge Routers
  • 1 T Series Core Routers
  • 1 EX Series Ethernet Switches
  • 1 J Series Services Routers

Overview and Topology

The physical topology of the Layer 2 VPN to Layer 2 VPN connection example is shown in Figure 1.

Figure 1: Physical Topology of a Layer 2 VPN to Layer 2 VPN Connection

Physical Topology of a Layer 2 VPN to Layer 2 VPN Connection

The logical topology of a Layer 2 VPN to Layer 2 VPN connection is shown in Figure 2.

Figure 2: Logical Topology of a Layer 2 VPN to Layer 2 VPN Connection

Logical Topology of a Layer 2 VPN to Layer 2 VPN Connection

Configuration

Note: In any configuration session, it is good practice to verify periodically that the configuration can be committed using the commit check command.

In this example, the router being configured is identified using the following command prompts:

  • CE1 identifies the customer edge 1 (CE1) router
  • PE1 identifies the provider edge 1 (PE1) router
  • CE3 identifies the customer edge 3 (CE3) router
  • PE3 identifies the provider edge 3 (PE3) router
  • CE5 identifies the customer edge 5 (CE5) router
  • PE5 identifies the provider edge 5 (PE5) router

This example is organized in the following sections:

Configuring Protocols on the PE and P Routers

Step-by-Step Procedure

All of the PE routers and P routers are configured with OSPF as the IGP protocol. The MPLS, LDP, and BGP protocols are enabled on all of the interfaces except fxp.0. Core-facing interfaces are enabled with the MPLS address and inet address.

  1. Configure all the PE and P routers with OSPF as the IGP. Enable the MPLS, LDP, and BGP protocols on all interfaces except fxp.0. The following configuration snippet shows the protocol configuration for Router PE1:
    [edit]
    protocols {mpls {interface all;interface fxp0.0 {disable;}}bgp {group RR {type internal;local-address 1.1.1.1;family l2vpn {signaling;}neighbor 7.7.7.7;}}ospf {traffic-engineering;area 0.0.0.0 {interface all;interface fxp0.0 {disable;}}}ldp {interface all;interface fxp0.0 {disable;}}}
  2. Configure the PE and P routers with OSPF as the IGP. Enable the MPLS, LDP, and BGP protocols on all interfaces except fxp.0. The following configuration snippet shows the protocol configuration for Router PE3:
    [edit]
    protocols {mpls {interface all;interface fxp0.0 {disable;}}bgp {group RR {type internal;local-address 3.3.3.3;family l2vpn {signaling;}neighbor 7.7.7.7;}}ospf {traffic-engineering;area 0.0.0.0 {interface all;interface fxp0.0 {disable;}}}ldp {interface all;interface fxp0.0 {disable;}}}

Step-by-Step Procedure

Configuring the Layer 2 VPN Protocol and Interfaces

  1. On Router PE1, configure the ge-1/0/0 interface encapsulation. To configure the interface encapsulation, include the encapsulation statement and specify the ethernet-ccc option (vlan-ccc encapsulation is also supported). Configure the ge-1/0/0.0 logical interface family for circuit cross-connect functionality. To configure the logical interface family, include the family statement and specify the ccc option. The encapsulation should be configured the same way for all routers in the Layer 2 VPN domain.
    [edit interfaces]
    ge-1/0/0 {encapsulation ethernet-ccc;unit 0 {family ccc;}}
    lo0 {unit 0 {family inet {address 1.1.1.1/32;}}}
  2. On Router PE1, configure the Layer 2 VPN protocols. Configure the remote site ID as 3. Site ID 3 represents Router PE3 (Hub-PE). To configure the Layer 2 VPN protocols, include the l2vpn statement at the [edit routing-instances routing-instances-name protocols] hierarchy level. Layer 2 VPNs use BGP as the signaling protocol.
    [edit routing-instances]
    L2VPN {instance-type l2vpn;interface ge-1/0/0.0;route-distinguisher 65000:1;vrf-target target:65000:2;protocols {l2vpn {encapsulation-type ethernet;site CE1 {site-identifier 1;interface ge-1/0/0.0 {remote-site-id 3;}}}}}
  3. On Router PE5, configure the ge-2/0/0 interface encapsulation by including the encapsulation statement and specify the ethernet-ccc option. Configure the ge-1/0/0.0 logical interface family for circuit cross-connect functionality by including the family statement and specifying the ccc option.
    [edit interfaces]
    ge-2/0/0 {encapsulation ethernet-ccc;unit 0 {family ccc;}}
    lo0 {unit 0 {family inet {address 5.5.5.5/32;}}}
  4. On Router PE5, configure the Layer 2 VPN protocols by including the l2vpn statement at the [edit routing-instances routing-instances-name protocols] hierarchy level. Configure the remote site ID as 3.
    [edit routing-instances]
    L2VPN {instance-type l2vpn;interface ge-2/0/0.0;route-distinguisher 65000:5;vrf-target target:65000:2;protocols {l2vpn {encapsulation-type ethernet;site CE5 {site-identifier 5;interface ge-2/0/0.0 {remote-site-id 3;}}}}}
  5. On Router PE3, configure the iw0 interface with two logical interfaces. To configure the iw0 interface, include the interfaces statement and specify iw0 as the interface name. For the unit 0 logical interface, include the peer-unit statement and specify the logical interface unit 1 as the peer interface. For the unit 1 logical interface, include the peer-unit statement and specify the logical interface unit 0 as the peer interface.
    [edit interfaces]
    iw0 {unit 0 {encapsulation ethernet-ccc;peer-unit 1;}unit 1 {encapsulation ethernet-ccc;peer-unit 0;}}
  6. On Router PE3, configure the edge-facing ge-1/0/1 interface encapsulation by including the encapsulation statement and specifying the ethernet-ccc option.
    [edit interfaces]
    ge-1/0/1 {encapsulation ethernet-ccc;unit 0 {family ccc;}}
  7. On Router PE3, configure the logical loopback interface. The loopback interface is used to establish the targeted LDP sessions to Routers PE1 and Router PE5.
    [edit interfaces]
    lo0 {unit 0 {family inet {address 3.3.3.3/32;}}}
  8. On Router PE3, enable the Layer 2 interworking protocol. To enable the Layer 2 interworking protocol, include the l2iw statement at the [edit protocols] hierarchy level.
    [edit protocols]l2iw;
  9. On Router PE3, configure two Layer 2 VPN routing instances to terminate the Layer 2 VPN virtual circuits from Router PE1 and Router PE5, as shown.
    [edit routing-instances]
    L2VPN-PE1 {instance-type l2vpn;interface iw0.0;route-distinguisher 65000:3;vrf-target target:65000:2;protocols {l2vpn {encapsulation-type ethernet;site CE3 {site-identifier 3;interface iw0.0 {remote-site-id 1;}}}}}
    L2VPN-PE5 {instance-type l2vpn;interface iw0.1;route-distinguisher 65000:33;vrf-target target:65000:2;protocols {l2vpn {encapsulation-type ethernet;site CE3 {site-identifier 3;interface iw0.1 {remote-site-id 5;}}}}}

Verifying the Layer 2 VPN to Layer 2 VPN Connection on Router PE3

Step-by-Step Procedure

  1. BGP is used for control plane signaling in a Layer 2 VPN. On Router PE1, use the show bgp command to verify that the BGP control plane for the Layer 2 VPN, has established a neighbor relationship with the route reflector that has IP address 7.7.7.7.

    Three Layer 2 VPN routes are received from the route reflector for each PE router in the topology.

    user@PE1> show bgp summary
    Groups: 1 Peers: 1 Down peers: 0
Table          Tot Paths  Act Paths Suppressed    History Damp State    Pending
bgp.l2vpn.0            3          3          0          0          0          0
Peer                     AS      InPkt     OutPkt    OutQ   Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
7.7.7.7               65000        190        192       0       0     1:24:40 Establ
  bgp.l2vpn.0: 3/3/3/0
  L2VPN.l2vpn.0: 3/3/3/0
  2. On Router PE1, use the show route command to verify that the BGP Layer 2 VPN routes are stored in the L2VPN.l2vpn.0 routing table for each PE router.
    user@PE1> show route table L2VPN.l2vpn.0 
    L2VPN.l2vpn.0: 4 destinations, 4 routes (4 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
65000:1:1:3/96                
                   *[L2VPN/170/-101] 01:31:53, metric2 1
                      Indirect
65000:3:3:1/96                
                   *[BGP/170] 01:24:58, localpref 100, from 7.7.7.7
                      AS path: I
                    > to 10.10.1.2 via xe-0/3/0.0
65000:5:5:3/96                
                   *[BGP/170] 01:24:58, localpref 100, from 7.7.7.7
                      AS path: I
                    > to 10.10.3.2 via xe-0/2/0.0
65000:33:3:5/96                
                   *[BGP/170] 01:24:58, localpref 100, from 7.7.7.7
                      AS path: I
                    > to 10.10.1.2 via xe-0/3/0.0
  3. On Router PE1, use the show ldp session command to verify that targeted LDP sessions are established to the PE routers in the network and that the state is Operational.
    user@PE1> show ldp session 
      Address           State        Connection     Hold time
2.2.2.2             Operational  Open             24
3.3.3.3             Operational  Open             22
5.5.5.5             Operational  Open             28
  4. On Router PE1, use the show l2vpn connections command to verify that the Layer 2 VPN to site 3 on Router PE3 (Hub-PE) is Up.
    user@PE1> show l2vpn connections
    Layer-2 VPN connections:

Legend for connection status (St)   
EI -- encapsulation invalid      NC -- interface encapsulation not CCC/TCC/VPLS
EM -- encapsulation mismatch     WE -- interface and instance encaps not same
VC-Dn -- Virtual circuit down    NP -- interface hardware not present 
CM -- control-word mismatch      -> -- only outbound connection is up
CN -- circuit not provisioned    <- -- only inbound connection is up
OR -- out of range               Up -- operational
OL -- no outgoing label          Dn -- down                      
LD -- local site signaled down   CF -- call admission control failure      
RD -- remote site signaled down  SC -- local and remote site ID collision
LN -- local site not designated  LM -- local site ID not minimum designated
RN -- remote site not designated RM -- remote site ID not minimum designated
XX -- unknown connection status  IL -- no incoming label
MM -- MTU mismatch               MI -- Mesh-Group ID not availble
BK -- Backup connection          ST -- Standby connection
PF -- Profile parse failure      PB -- Profile busy

Legend for interface status 
Up -- operational           
Dn -- down

Instance: L2VPN
  Local site: CE1 (1)
    connection-site           Type  St     Time last up          # Up trans
    3                         rmt   Up     Jan  5 18:08:25 2010           1
      Remote PE: 3.3.3.3, Negotiated control-word: Yes (Null)
      Incoming label: 800000, Outgoing label: 800000
      Local interface: ge-1/0/0.0, Status: Up, Encapsulation: ETHERNET
    5                         rmt   OR
  5. On Router PE1, use the show route command to verify that the mpls.0 routing table is populated with the Layer 2 VPN routes used to forward the traffic using an LDP label. Notice that in this example, the router is pushing label 8000000.
    user@PE1> show route table mpls.0
    [edit]
mpls.0: 13 destinations, 13 routes (13 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

0                  *[MPLS/0] 1w1d 11:36:44, metric 1
                      Receive
1                  *[MPLS/0] 1w1d 11:36:44, metric 1
                      Receive
2                  *[MPLS/0] 1w1d 11:36:44, metric 1
                      Receive
300432             *[LDP/9] 3d 04:25:02, metric 1
                    > to 10.10.2.2 via xe-0/1/0.0, Pop      
300432(S=0)        *[LDP/9] 3d 04:25:02, metric 1
                    > to 10.10.2.2 via xe-0/1/0.0, Pop      
300768             *[LDP/9] 3d 04:25:02, metric 1
                    > to 10.10.3.2 via xe-0/2/0.0, Pop      
300768(S=0)        *[LDP/9] 3d 04:25:02, metric 1
                    > to 10.10.3.2 via xe-0/2/0.0, Pop      
300912             *[LDP/9] 3d 04:25:02, metric 1
                    > to 10.10.3.2 via xe-0/2/0.0, Swap 299856
301264             *[LDP/9] 3d 04:24:58, metric 1
                    > to 10.10.1.2 via xe-0/3/0.0, Swap 308224
301312             *[LDP/9] 3d 04:25:01, metric 1
                    > to 10.10.1.2 via xe-0/3/0.0, Pop      
301312(S=0)        *[LDP/9] 3d 04:25:01, metric 1
                    > to 10.10.1.2 via xe-0/3/0.0, Pop      
800000             *[L2VPN/7] 01:25:28
                    > via ge-1/0/0.0, Pop       Offset: 4    
ge-1/0/0.0         *[L2VPN/7] 01:25:28, metric2 1
                    > to 10.10.1.2 via xe-0/3/0.0, Push 800000 Offset: -4

Verifying the Layer 2 VPN to Layer 2 VPN Connection on Router PE3

Step-by-Step Procedure

  1. On Router PE3, use the show l2vpn connections command to verify that the Layer 2 VPN connections from Router PE1 and Router PE5 are Up and are using the iw0 interface.
    user@PE3> show l2vpn connections
    Instance: L2VPN-PE1
  Local site: CE3 (3)
    connection-site           Type  St     Time last up          # Up trans
    1                         rmt   Up     Jan  5 18:08:22 2010           1
      Remote PE: 1.1.1.1, Negotiated control-word: Yes (Null)
      Incoming label: 800000, Outgoing label: 800000
      Local interface: iw0.0, Status: Up, Encapsulation: ETHERNET
    5                         rmt   OR   

Instance: L2VPN-PE5
  Local site: CE3 (3)
    connection-site           Type  St     Time last up          # Up trans
    1                         rmt   CN   
    5                         rmt   Up     Jan  5 18:08:22 2010           1
      Remote PE: 5.5.5.5, Negotiated control-word: Yes (Null)
      Incoming label: 800002, Outgoing label: 800000
      Local interface: iw0.1, Status: Up, Encapsulation: ETHERNET
  2. On Router PE3, use the show ldp neighbor command to verify that the targeted LDP session neighbor IP addresses are shown.
    user@PE3> show ldp neighbor 
    Address            Interface          Label space ID         Hold time
1.1.1.1            lo0.0              1.1.1.1:0                44
2.2.2.2            lo0.0              2.2.2.2:0                42
4.4.4.4            lo0.0              4.4.4.4:0                31
5.5.5.5            lo0.0              5.5.5.5:0                44
  3. On Router PE3, use the show bgp summary command to verify that the BGP control plane for the Layer 2 VPN, has established a neighbor relationship with the route reflector that has IP address 7.7.7.7.
    user@PE3> show bgp summary 
    Groups: 1 Peers: 1 Down peers: 0
Table          Tot Paths  Act Paths Suppressed    History Damp State    Pending
bgp.l2vpn.0            2          2          0          0          0          0
Peer                     AS      InPkt     OutPkt    OutQ   Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
7.7.7.7               65000      10092      10195       0       0  3d 4:23:27 Establ
  bgp.l2vpn.0: 2/2/2/0
  L2VPN-PE1.l2vpn.0: 2/2/2/0
  L2VPN-PE5.l2vpn.0: 2/2/2/0
  4. On Router PE3, use the show ldp session command to verify that targeted LDP sessions are established to all of the PE routers in the network and that the state is Operational.
    user@PE3> show ldp session 
    Address           State        Connection     Hold time
1.1.1.1             Operational  Open             24
2.2.2.2             Operational  Open             22
4.4.4.4             Operational  Open             20
5.5.5.5             Operational  Open             24
  5. On Router PE3, use the show route command to verify that the mpls.0 routing table is populated with the Layer 2 VPN routes used to forward the traffic using an LDP label. Notice that in this example, the router is swapping label 800000. Also notice the two iw0 interfaces that are used for the Layer 2 interworking routes.
    user@PE3>show route table mpls.0 
    mpls.0: 16 destinations, 18 routes (16 active, 2 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

0                  *[MPLS/0] 1w1d 11:50:14, metric 1
                      Receive
1                  *[MPLS/0] 1w1d 11:50:14, metric 1
                      Receive
2                  *[MPLS/0] 1w1d 11:50:14, metric 1
                      Receive
308160             *[LDP/9] 3d 04:38:45, metric 1
                    > to 10.10.1.1 via xe-0/3/0.0, Pop      
308160(S=0)        *[LDP/9] 3d 04:38:45, metric 1
                    > to 10.10.1.1 via xe-0/3/0.0, Pop      
308176             *[LDP/9] 3d 04:38:44, metric 1
                    > to 10.10.6.2 via xe-0/1/0.0, Pop      
308176(S=0)        *[LDP/9] 3d 04:38:44, metric 1
                    > to 10.10.6.2 via xe-0/1/0.0, Pop      
308192             *[LDP/9] 00:07:18, metric 1
                    > to 10.10.20.1 via xe-0/0/0.0, Swap 601649
                      to 10.10.6.2 via xe-0/1/0.0, Swap 299856
308208             *[LDP/9] 3d 04:38:44, metric 1
                    > to 10.10.5.1 via xe-0/2/0.0, Pop      
308208(S=0)        *[LDP/9] 3d 04:38:44, metric 1
                    > to 10.10.5.1 via xe-0/2/0.0, Pop      
308224             *[LDP/9] 3d 04:38:42, metric 1
                    > to 10.10.20.1 via xe-0/0/0.0, Pop      
308224(S=0)        *[LDP/9] 3d 04:38:42, metric 1
                    > to 10.10.20.1 via xe-0/0/0.0, Pop      
800000             *[L2IW/6] 01:39:13, metric2 1
                    > to 10.10.6.2 via xe-0/1/0.0, Swap 800000  
                    [L2VPN/7] 01:39:13
                    > via iw0.0, Pop       Offset: 4
800002             *[L2IW/6] 01:39:13, metric2 1                     
                    > to 10.10.1.1 via xe-0/3/0.0, Swap 800000    
                    [L2VPN/7] 01:39:13
                    > via iw0.1, Pop       Offset: 4
iw0.0              *[L2VPN/7] 01:39:13, metric2 1
                    > to 10.10.1.1 via xe-0/3/0.0, Push 800000 Offset: -4
iw0.1              *[L2VPN/7] 01:39:13, metric2 1
                    > to 10.10.6.2 via xe-0/1/0.0, Push 800000 Offset: -4

Step-by-Step Procedure

Testing Layer 2 VPN to Layer 2 VPN Connectivity (CE1 to CE5)

  1. On Router CE1, use the ping command to test connectivity to Router CE5. Notice that the response time is in milliseconds, confirming that the ping response is returned.
    user@CE1>ping 40.40.40.11
    PING 40.40.40.11 (40.40.40.11): 56 data bytes
64 bytes from 40.40.40.11: icmp_seq=1 ttl=64 time=22.425 ms
64 bytes from 40.40.40.11: icmp_seq=2 ttl=64 time=1.299 ms
64 bytes from 40.40.40.11: icmp_seq=3 ttl=64 time=1.032 ms
64 bytes from 40.40.40.11: icmp_seq=4 ttl=64 time=1.029 ms
  2. On Router CE5, use the ping command to test connectivity to Router CE1. Notice that the response time is in milliseconds, confirming that the ping response is returned.
    user@CE5>ping 40.40.40.1
    PING 40.40.40.1 (40.40.40.1): 56 data bytes
64 bytes from 40.40.40.1: icmp_seq=0 ttl=64 time=1.077 ms
64 bytes from 40.40.40.1: icmp_seq=1 ttl=64 time=0.957 ms
64 bytes from 40.40.40.1: icmp_seq=2 ttl=64 time=1.057 ms 1.017 ms

Results

The configuration and verification of this example have been completed. The following section is for your reference.

The relevant sample configuration for Router PE1 follows.

Router PE1

chassis {dump-on-panic;fpc 1 {pic 3 {tunnel-services {bandwidth 1g;}}}network-services ethernet;}interfaces {xe-0/1/0 {unit 0 {family inet {address 10.10.2.1/30;}family mpls;}}xe-0/2/0 {unit 0 {family inet {address 10.10.3.1/30;}family mpls;}}xe-0/3/0 {unit 0 {family inet {address 10.10.1.1/30;}family mpls;}}ge-1/0/0 {encapsulation ethernet-ccc;unit 0 {family ccc;}}lo0 {unit 0 {family inet {address 1.1.1.1/32;}}}}routing-options {static {route 172.0.0.0/8 next-hop 172.19.59.1;}autonomous-system 65000;}protocols {mpls {interface all;interface fxp0.0 {disable;}}bgp {group RR {type internal;local-address 1.1.1.1;family l2vpn {signaling;}neighbor 7.7.7.7;}}ospf {traffic-engineering;area 0.0.0.0 {interface all;interface fxp0.0 {disable;}}}ldp {interface all;interface fxp0.0 {disable;}}}routing-instances {L2VPN {instance-type l2vpn;interface ge-1/0/0.0;route-distinguisher 65000:1;vrf-target target:65000:2;protocols {l2vpn {encapsulation-type ethernet;site CE1 {site-identifier 1;interface ge-1/0/0.0 {remote-site-id 3;}}}}}}

The relevant sample configuration for Router PE3 follows.

Router PE3

chassis {dump-on-panic;fpc 1 {pic 3 {tunnel-services {bandwidth 1g;}}}network-services ethernet;}
interfaces {xe-0/0/0 {unit 0 {family inet {address 10.10.20.2/30;}family mpls;}}xe-0/1/0 {unit 0 {family inet {address 10.10.6.1/30;}family mpls;}}xe-0/2/0 {unit 0 {family inet {address 10.10.5.2/30;}family mpls;}}xe-0/3/0 {unit 0 {family inet {address 10.10.1.2/30;}family mpls;}}ge-1/0/1 {encapsulation ethernet-ccc;unit 0 {family ccc;}}iw0 {unit 0 {encapsulation ethernet-ccc;peer-unit 1;}unit 1 {encapsulation ethernet-ccc;peer-unit 0;}}lo0 {unit 0 {family inet {address 3.3.3.3/32;}}}}
routing-options {static {route 172.0.0.0/8 next-hop 172.19.59.1;}autonomous-system 65000;}
protocols {l2iw;mpls {interface all;interface fxp0.0 {disable;}}bgp {group RR {type internal;local-address 3.3.3.3;family l2vpn {signaling;}neighbor 7.7.7.7;}}ospf {area 0.0.0.0 {interface all;interface fxp0.0 {disable;}}}ldp {interface all;interface fxp0.0 {disable;}}}
routing-instances {L2VPN-PE1 {instance-type l2vpn;interface iw0.0;route-distinguisher 65000:3;vrf-target target:65000:2;protocols {l2vpn {encapsulation-type ethernet;site CE3 {site-identifier 3;interface iw0.0 {remote-site-id 1;}}}}}L2VPN-PE5 {instance-type l2vpn;interface iw0.1;route-distinguisher 65000:33;vrf-target target:65000:2;protocols {l2vpn {encapsulation-type ethernet;site CE3 {site-identifier 3;interface iw0.1 {remote-site-id 5;}}}}}}
 

Related Documentation

 

Published: 2013-07-31

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