4000 Router Series MPLS Configuration Guide

Configuring tunnel policies

Overview

Tunnel policies enable a PE to forward traffic for each MPLS VPN over a preferred tunnel or over multiple

tunnels when the PE has multiple tunnels to the peer PE. The tunnels supported by MPLS VPN include

MPLS LSPs, MPLS TE tunnels, and GRE tunnels.

For more information about MPLS TE, see "Configuring MPLS TE." For more information about GRE, see

Layer 3—IP Services Configuration Guide. For more information about MPLS VPNs, see "Configuring

MPLS L3VPN."

Configuring a tunnel policy

Configuration guidelines

• To select a preferred tunnel, create a tunnel policy and specify the preferred tunnel with the

preferred-path command. The destination address of the preferred tunnel identifies a peer PE so the

PE will forward traffic destined for that peer PE over the preferred tunnel. If you specify multiple

preferred tunnels that have the same destination address in a tunnel policy, only the first configured

tunnel takes effect. If the first tunnel is not available, the second tunnel is used, and so forth. No load

balancing will be performed on these tunnels. This method explicitly specifies an MPLS TE or GRE

tunnel for an MPLS VPN, facilitating traffic planning. HP recommends that you use this method.

• To select multiple tunnels for load sharing, create a tunnel policy and specify the tunnel selection

order and the number of tunnels by using the select-seq load-balance-number command. A tunnel

type closer to the select-seq keyword has a higher priority. For example, the select-seq lsp gre

load-balance-number 3 command gives LSP higher priority over GRE. If no LSP is available or the

number of LSPs is less than 3, VPN uses GRE tunnels. The tunnels selected by this method are not

fixed, complicating traffic planning. HP recommends not using this method.

If you configure both methods for a tunnel policy, the tunnel policy selects tunnels in the following steps:

1. If the destination address of a preferred tunnel identifies a peer PE, the tunnel policy uses the

preferred tunnel to forward traffic destined for the peer PE without using any other tunnels.

2. If not, the tunnel policy selects tunnels as configured by the select-seq load-balance-number

command.