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Example: Configuring FAT Pseudowire Support for BGP L2VPN to Load-Balance MPLS Traffic

 

This example shows how to implement FAT pseudowire support for BGP L2VPN to help load-balance MPLS traffic.

Requirements

This example uses the following hardware and software components:

  • Five MX Series routers

  • Junos OS Release 16.1 or later running on all devices

Before you configure FAT pseudowire support for BGP L2VPN, be sure you configure the routing and signaling protocols.

Overview

Junos OS allows the flow-aware transport (FAT) flow label that is supported for BGP-signaled pseudowires such as L2VPN to be configured only on the label edge routers (LERs). This causes the transit routers or the label-switching routers(LSRs) to perform load balancing of MPLS packets across equal-cost multipath (ECMP) paths or link aggregation groups (LAGs) without the need for deep packet inspection of the payload. The FAT flow label can be used for LDP-signaled forwarding equivalence class (FEC 128 and FEC 129) pseudowires for VPWS and VPLS pseudowires.

Topology

Figure 1, shows the FAT pseudowire support for BGP L2VPN configured on Device PE1 and Device PE2.

Figure 1: Example FAT Pseudowire Support for BGP L2VPN
Example FAT Pseudowire Support for BGP
L2VPN

Configuration

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, copy and paste the commands into the CLI at the [edit] hierarchy level, and then enter commit from configuration mode.

CE1

PE1

P

PE2

CE2

Configuring PE1

Step-by-Step Procedure

The following example requires that you navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the CLI User Guide.

To configure Device PE1:

  1. Configure the interfaces.
  2. Configure nonstop routing, and configure the router ID.
  3. Configure the autonomous system (AS) number, and apply the policy to the forwarding table of the local router with the export statement.
  4. Configure the RSVP protocol on the interfaces.
  5. Apply the label-switched path attributes to the MPLS protocol, and configure the interface.
  6. Define a peer group, and configure the address of the local-end address of the BGP session for peer group vpls-pe.
  7. Configure attributes of the protocol family for NLRIs in updates.
  8. Configure neighbors for the peer group vpls-pe.
  9. Configure traffic engineering, and configure the interfaces of OSPF area 0.0.0.0.
  10. Configure the routing policy and the BGP community information.
  11. Configure the type of routing instance, and configure the interface.
  12. Configure the route distinguisher for instance l2vpn-inst, and configure the VRF target community.
  13. Configure the type of encapsulation required for the L2VPN protocol.
  14. Configure the sites connected to the provider equipment.
  15. Configure the L2VPN protocol for the routing instance to provide advertising capability to pop the flow label in the receive direction to the remote PE and to provide advertising capability to push the flow label in the transmit direction to the remote PE.
  16. Configure the type of routing instance, and configure the interface.
  17. Configure the route distinguisher for instance vp1, and configure the VRF target community.
  18. Assign the maximum site identifier for the VPLS domain.
  19. Configure to not use the tunnel services for the VPLS instance, and assign a site identifier to the site connected to the provider equipment.
  20. Configure the VPLS protocol for the routing instance to provide advertising capability to pop the flow label in the receive direction to the remote PE and to provide advertising capability to push the flow label in the transmit direction to the remote PE.

Results

From configuration mode, confirm your configuration by entering the show interfaces, show protocols, show policy-options, show routing-instances, and show routing-options commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.

Verification

Confirm that the configuration is working properly.

Verifying the BGP Summary Information

Purpose

Verify the BGP summary information.

Action

From operational mode, enter the show bgp summary command.

user@PE1> show bgp summary

Meaning

The output displays the BGP summary information.

Verifying the L2VPN Connections Information

Purpose

Verify the Layer 2 VPN connections information.

Action

From operational mode, run the show l2vpn connections command to display the Layer 2 VPN connections information.

user@PE1> show l2vpn connections

Meaning

The output displays the Layer 2 VPN connections information along with the flow label transmit and flow label receive information.

Verifying the Routes

Purpose

Verify that the expected routes are learned.

Action

From operational mode, run the show route command to display the routes in the routing table.

user@PE1> show route

Meaning

The output shows all the routes in the routing table.

Configuring PE2

Step-by-Step Procedure

The following example requires that you navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the CLI User Guide.

To configure Device PE2:

  1. Configure the interfaces.
  2. Configure the router ID.
  3. Configure the autonomous system (AS) number, and apply the policy to the forwarding table of the local router with the export statement.
  4. Configure the RSVP protocol on the interfaces.
  5. Apply the label-switched path attributes to the MPLS protocol, and configure the interface.
  6. Define a peer group, and configure the local-end address of the BGP session for the peer group vpls-pe.
  7. Configure the attributes of the protocol family for NLRIs in updates.
  8. Configure the neighbors for peer group vpls-pe.
  9. Configure traffic engineering, and configure the interfaces of OSPF area 0.0.0.0.
  10. Configure the routing policy and the BGP community information.
  11. Configure the type of routing instance, and configure the interface.
  12. Configure the route distinguisher for instance l2vpn-inst, and configure the VRF target community.
  13. Configure the type of encapsulation required for the L2VPN protocol.
  14. Configure the sites connected to the provider equipment.
  15. Configure the L2VPN protocol for the routing instance to provide advertising capability to pop the flow label in the receive direction to the remote PE and to provide advertising capability to push the flow label in the transmit direction to the remote PE.
  16. Configure the type of routing instance, and configure the interface.
  17. Configure the route distinguisher for instance vpl1, and configure the VRF target community.
  18. Assign the maximum site identifier for the VPLS domain.
  19. Configure to not use the tunnel services for the VPLS instance, and assign a site identifier to the site connected to the provider equipment.
  20. Configure the VPLS protocol for the routing instance to provide advertising capability to pop the flow label in the receive direction to the remote PE and to provide advertising capability to the push flow label in the transmit direction to the remote PE.

Results

From configuration mode, confirm your configuration by entering the show interfaces, show protocols, show policy-options, show routing-instances, and show routing-options commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.

Verification

Confirm that the configuration is working properly.

Verifying the BGP Summary Information

Purpose

Verify the BGP summary information.

Action

From operational mode, enter the show bgp summary command.

user@PE2> show bgp summary

Meaning

The output displays the BGP summary information.

Verifying the L2VPN Connections Information

Purpose

Verify the Layer 2 VPN connections information.

Action

From operational mode, run the show l2vpn connections command to display the Layer 2 VPN connections information.

user@PE2> show l2vpn connections

Meaning

The output displays the Layer 2 VPN connections information along with the flow label transmit and flow label receive information.

Verifying the Routes

Purpose

Verify that the expected routes are learned.

Action

From operational mode, run the show route command to display the routes in the routing table.

user@PE2> show route

Meaning

The output shows all the routes in the routing table.