H-VPLS N-PE Redundancy for MPLS Access

This chapter contains the following sections:

H-VPLS

The H-VPLS N-PE Redundancy for MPLS Access feature enables two network provider edge (N-PE) devices to provide failover services to a user provider edge (U-PE) device in a hierarchical virtual private LAN service (H-VPLS). Redundant N-PE devices increase stability and reliability by protecting against link and node failures. If a failure occurs in the network that disables one N-PE device from transmitting data, the other N-PE device takes over.

Table 1. Feature History Table

Feature name

Release information

Feature description

H-VPLS N-PE Redundancy for MPLS Access

Release 17.18.2

This feature enables a U‑PE to connect to two N‑PEs using active/backup pseudowires, delivering rapid switchover on link or node failure without service reconfiguration.

Prerequisites for H-VPLS

  • Configure your H-VPLS network.

  • Enable the MPLS Traffic Engineering-Fast Reroute feature in the MPLS core to improve convergence.

  • Enable the L2VPN Pseudowire Redundancy feature on the U-PE devices for MPLS access.

Restrictions for H-VPLS

  • You cannot use this feature with the VPLS Autodiscovery feature on pseudowires that connect to U-PE devices. When you create the virtual private LAN service (VPLS), manually create the virtual forwarding interface (VFI).

  • You cannot configure more than one pseudowire to carry the bridge protocol data unit (BPDU) information between the network provider edge (N-PE) devices.

  • You cannot configure a local loopback address as a neighbor when you configure the H-VPLS N-PE Redundancy feature on N-PE devices.

  • Only two N-PE devices can be connected to each U-PE device.

H-VPLS N-PE redundancy with MPLS access based on pseudowire redundancy

For H-VPLS Redundancy with MPLS Access, the MPLS network uses redundant pseudowires. These pseudowires connect the MPLS network to N-PE devices in the VPLS core.

As shown in the figure, a primary pseudowire carries data between the U-PE and N-PE devices. If the U-PE path fails, a backup pseudowire and redundant N-PE device activate to continue data transport.

Figure 1. H-VPLS N-PE redundancy for MPLS access based on pseudowire Redundancy

Configuration of H-VPLS N-PE Redundancy for MPLS Access

Specify the devices in the layer 2 VPN VFI

Before you begin

Ensure that the device is in configuration mode.

Procedure

Step 1

Use the l2vpn vfi context name command to establish a L2VPN VFI between two or more separate networks, and enter L2VFI configuration mode.

Example:

Device(config)# l2vpn vfi context VPLS-10

Step 2

Use the vpn id vpn id command to set a VPN ID on the VPLS instance.

Example:

Device(config-vfi)# vpn id 10

  • Use the same VPN ID for the PE devices that belong to the same VPN.

  • Make sure the VPN ID is unique for each VPN in the service provider network. The range is from 1 to 4294967295.

Step 3

Use the member ip address encapsulation mpls command to specify the device that forms a point-to-point L2VPN VFI connection.

Example:

Device(config-vfi)# member 102.102.102.102 encapsulation mpls

  • ip-address : IP address of the VFI neighbor (the N-PE device).

  • encapsulation mpls: specifies MPLS as the data encapsulation method.

Step 4

Use the exit command to return to global configuration mode.

Example:

Device(config-vfi)# exit

Step 5

Use the bridge domain bridge domain command to configure components on a bridge domain, and enter bridge-domain configuration mode.

Example:

Device(config)# bridge domain 10

Step 6

Use the member vfi vfi-name command to configure the VFI member in the bridge-domain.

Example:

Device(config-bdomain)# member vfi VPLS-10

Step 7

Use the member ip-address vc-id encapsulation mpls command to specify the device that forms a point-to-point L2VPN VFI connection.

Example:

Device(config-vfi)# member 105.105.105.105 10  encapsulation mpls

  • ip-address : IP address of the VFI neighbor (U-PE device).

  • vc-id : Virtual circuit identifier.

  • encapsulation mpls : Specifies MPLSas the data encapsulation method.

Specify the N-PE devices that form the layer 2 VPN cross connection with the U-PE

Before you begin

Ensure that the device is in configuration mode.

Procedure

Step 1

Use the interface type number command to specify the interface to configure, and enter interface configuration mode.

Example:

Device(config)# interface GigabitEthernet0/0/0

Step 2

Use the service instance id ethernet command to configure an ethernet service instance on the interface, and enter ethernet service configuration mode.

Example:

Device(config-if)# service instance 10 ethernet

Step 3

Use the encapsulation untagged command define the criteria to map tagged or untagged frame ingress on the interface to the appropriate service instance.

Example:

Device(config-if-srv)# encapsulation untagged

Step 4

Use the exit command to return to interface configuration mode.

Example:

Device(config-if-srv)# exit

Step 5

Use the exit command again to return to global configuration mode.

Example:

Device(config-if)# exit

Step 6

Use the l2vpn xconnect context context-name to create a L2VPN cross connect context, and enter xconnect configuration mode.

Example:

Device(config)# l2vpn xconnect context XC-10

Step 7

Use the member gigabitethernet interface-number [service-instance id] command to specify devices that form a L2VPN cross connect.

Example:

Device(config-xconnect)# member GigabitEthernet0/0/0 service-instance 10

service-instance id : (Optional) Specifies the service instance identifier.

Step 8

Use the member ip-address vc-id encapsulation mpls [group group-name [priority number] command to specify devices that form a L2VPN cross connect.

Example:

Device(config-xconnect)# member 101.101.101.101 10 encapsulation mpls group pwred priority 9

Device(config-xconnect)# member 102.102.102.102 10 encapsulation mpls group pwred priority 10

  • ip-address —IP address of the peer N-PE device.

  • vc-id —Virtual circuit identifier.

  • encapsulation mpls —Specifies Multiprotocol Label Switching (MPLS) as the data encapsulation method.

  • group group-name —Specifies the cross-connect member redundancy group name.

  • priority number —Specifies the cross-connect member priority. The range is from 0 to 16. The highest priority is 0. Lowest priority is 16.

Configuration Example for H-VPLS N-PE Redundancy for MPLS Access

Example of configuring H-VPLS N-PE redundancy for MPLS access

The figure displays a configuration for H-VPLS N-PE redundancy with MPLS access. There is no option to configure multihoming on access VPLS, so the xconnect command with priority is used on uPE1.

Figure 2. H-VPLS N-PE Redundancy with MPLS Access Topology

nPE1 Configuration 


l2vpn vfi context VPLS-10
 vpn id 10
 member 102.102.102.102 encapsulation mpls
 member 103.103.103.103 encapsulation mpls
!
bridge-domain 10
 member vfi VPLS-10
 member 105.105.105.105 10 encapsulation mpls

nPE2 Configuration


l2vpn vfi context VPLS-10
 vpn id 10 
 member 101.101.101.101 encapsulation mpls
 member 103.103.103.103 encapsulation mpls
!
bridge-domain 10
 member vfi VPLS-10
 member 105.105.105.105 10 encapsulation mpls

nPE3 Configuration


l2vpn vfi context VPLS-10
 vpn id 10
 member 101.101.101.101 encapsulation mpls 
 member 102.102.102.102 encapsulation mpls
!
bridge-domain 10
 member vfi VPLS-10

uPE1 Configuration


interface GigabitEthernet0/1/0
 service instance 10 ethernet
 encapsulation dot1q 10
!
l2vpn xconnect context XC-10
 member GigabitEthernet0/1/0 service-instance 10
 member 101.101.101.101 10 encapsulation mpls group pwred priority 9
 member 102.102.102.102 10 encapsulation mpls group pwred priority 10

Verification

Use the show commands to verify that H-VPLS N-PE redundancy for MPLS access is configured successfully.

Sample Output on uPE1 

Device# show xconnect peer 101.101.101.101 vcid 10

Legend:    XC ST=Xconnect State  S1=Segment1 State  S2=Segment2 State
  UP=Up       DN=Down            AD=Admin Down      IA=Inactive
  SB=Standby  HS=Hot Standby     RV=Recovering      NH=No Hardware

XC ST  Segment 1                         S1 Segment 2                         S2
------+---------------------------------+--+---------------------------------+--
UP pri   ac Gi0/1/0:10(Eth VLAN)         UP mpls 101.101.101.101:10           UP

Device# show xconnect peer 102.102.102.102 vcid 10

Legend:    XC ST=Xconnect State  S1=Segment1 State  S2=Segment2 State
  UP=Up       DN=Down            AD=Admin Down      IA=Inactive
  SB=Standby  HS=Hot Standby     RV=Recovering      NH=No Hardware

XC ST  Segment 1                         S1 Segment 2                         S2
------+---------------------------------+--+---------------------------------+--
IA pri   ac Gi0/1/0:10(Eth VLAN)         UP mpls 102.102.102.102:10           SB
Device#