R2511-HP MSR Router Series MPLS Configuration Guide(V5)
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Bypass tunnels are pre-established and require extra bandwidth. Use bypass tunnels to protect only
crucial interfaces or links.
You can define which type of LSPs can use bypass LSPs, whether a bypass LSP provides bandwidth
protection, and the sum of protected bandwidth.
The bandwidth of a bypass LSP is to protect the protected LSPs. To guarantee that a protected LSP can
always bind with the bypass LSP successfully, make sure the bandwidth assigned to the bypass LSP is not
less than the total bandwidth needed by all protected LSPs.
A bypass tunnel only forwards data traffic when a protected tunnel fails. To allow a bypass tunnel to also
forward data traffic when the protected tunnels are normal, you must make sure that the bypass tunnel
has adequate bandwidth.
A bypass tunnel cannot be used for services like VPN.
Before you configure FRR, complete the following tasks:
• Configure IGP, making sure that all LSRs are reachable.
• Configure basic MPLS.
• Configure basic MPLS TE.
• Establish an MPLS TE tunnel with RSVP-TE.
• Set up primary LSPs.
Enabling FRR on the ingress node of a protected LSP
Ste
p
Command
Remarks
1. Enter system view.
system-view N/A
2. Enter tunnel interface view of
the protected LSP.
interface tunnel tunnel-number N/A
3. Enable FRR.
mpls te fast-reroute Disabled by default.
4. Submit current tunnel
configuration.
mpls te commit N/A
Configuring a bypass tunnel on its PLR
After a tunnel is specified to protect an interface, its corresponding LSP becomes a bypass LSP. The setup
of a bypass LSP must be manually performed on the PLR. The configuration of a bypass LSP is similar to
that of a common LSP, but a bypass LSP cannot act as an LSP to be protected by another LSP at the same
time.
When specifying a bypass tunnel for an interface, ensure the following:
• The bypass tunnel is up.
• The protected interface is not the outgoing interface of the bypass tunnel.
Up to three bypass tunnels can be specified for a protected interface. The best-fit algorithm determines
which of them is used in case a failure occurs.
Your device has a restriction on links that use the same bypass tunnel so their total bandwidth does not
exceeds a specific value.
To configure a bypass tunnel on its PLR: