3com S7906E 安装指导
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Configuring CR-LSP Backup
CR-LSP backup provides end-to-end path protection to protect the entire LSP.
Configuration Prerequisites
Before configuring CR-LSP backup, do the following:
z
Configure MPLS basic capabilities
z
Configure MPLS TE basic capabilities
z
Configure MPLS TE tunnels
Configuration Procedure
Follow these steps to configure CR-LSP backup:
To do…
Use the command...
Remarks
Enter system view of the
ingress node
ingress node
system-view
––
Enter MPLS TE tunnel interface
view
view
interface
tunnel
tunnel-number
––
Configure the backup mode
used by the TE tunnel
used by the TE tunnel
mpls te backup
{ hot-standby
| ordinary }
Required
Tunnel backup is disabled by
default.
Tunnel backup is disabled by
default.
Submit current tunnel
configuration
configuration
mpls te commit
Required
CR-LSP backup should be configured at the ingress node of a tunnel. The system routes the primary
LSP and backup LSP automatically. You do not need to configure them.
LSP and backup LSP automatically. You do not need to configure them.
Configuring FRR
As mentioned earlier, Fast Reroute (FRR) provides quick but temporary per-link or per-node local
protection on an LSP.
protection on an LSP.
FRR uses bypass tunnels to protect primary tunnels. As bypass tunnels are pre-established, they
require extra bandwidth and are usually used to protect crucial interfaces or links only.
require extra bandwidth and are usually used to protect crucial interfaces or links only.
You can define which type of LSP can use bypass LSPs, and whether a bypass LSP provides
bandwidth protection as well as the sum of protected bandwidth.
bandwidth protection as well as the sum of protected bandwidth.
The bandwidth of a bypass LSP is to protect its primary LSPs. To guarantee that a primary LSP can
always bind with the bypass LSP successfully, make sure that the bandwidth assigned to the bypass
LSP is not less than the total bandwidth needed by all protected LSPs.
always bind with the bypass LSP successfully, make sure that the bandwidth assigned to the bypass
LSP is not less than the total bandwidth needed by all protected LSPs.
Normally, bypass tunnels only forward data traffic when protected primary tunnels fail. To allow a
bypass tunnel forward data traffic while protecting the primary tunnel, you need to ensure that bypass
tunnels are available with adequate bandwidth.
bypass tunnel forward data traffic while protecting the primary tunnel, you need to ensure that bypass
tunnels are available with adequate bandwidth.