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Configuring tunnel policies
Overview
Tunnel policies enable a PE to forward traffic for each MPLS VPN over a preferred tunnel or over multiple
tunnels. The tunnels supported by MPLS VPN include MPLS LSPs and MPLS TE tunnels.
For more information about MPLS TE, see "
." For more information about MPLS
VPNs, see "
," "
."
Configuring a tunnel policy
Configuration guidelines
Follow these guidelines when you configure a tunnel policy:
•
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 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
cr-lsp
load-balance-number
3
command gives LSP higher priority. If no LSP is available or the number of
LSPs is less than 3, VPN uses CRLSP 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.
