mpls te backup

Function

The mpls te backup command specifies the backup mode of an existing tunnel.

The undo mpls te backup command restores the default configuration.

By default, no tunnel is backed up.

Format

mpls te backup ordinary [ best-effort ]

mpls te backup hot-standby [ mode { revertive [ wtr interval ] | non-revertive } | dynamic-bandwidth ] ^*

mpls te backup hot-standby wtr interval [ dynamic-bandwidth ]

mpls te backup hot-standby dynamic-bandwidth wtr interval

undo mpls te backup { hot-standby [ mode { revertive [ wtr [ interval ] ] | non-revertive } | dynamic-bandwidth ] ^* | ordinary }

Parameters

Parameter	Description	Value
ordinary	Enables the ordinary backup mode. In ordinary backup mode, an ordinary backup CR-LSP is created only after the primary CR-LSP fails.	-
hot-standby	Enables the hot-standby mode. In hot-standby mode, both the primary and backup CR-LSP are set up. If the primary CR-LSP fails, traffic is immediately switched to the hot-standby CR-LSP.	-
dynamic-bandwidth	Enables the dynamic bandwidth function for a hot-standby CR-LSP.	-
wtr interval	Specifies the wait-to-restore (WTR) time in hot standby.	The value is an integer that ranges from 0 to 2592000, in seconds. The default value is 10 seconds.
best-effort	Enables the best-effort path mode. When both the primary and backup CR-LSPs fail, the system triggers the establishment of a best-effort path.	-
mode { revertive \| non-revertive }	Specifies the revertive mode. revertive: The current mode can be switched to the original mode. non-revertive: The current mode cannot be switched to the original mode.	The default mode is revertive.

Views

Tunnel interface view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

To help enhance the reliability of a CR-LSP, you are recommended to set up a backup CR-LSP to protect traffic on the primary CR-LSP.

You can select the following CR-LSP backup modes as required:

Hot-standby mode: A hot-standby backup CR-LSP is set up over a separate path immediately after the primary CR-LSP is set up. When the CR-LSP transmitting services fails, traffic can be immediately switched to the other CR-LSP. However, additional bandwidth is needed in hot-standby mode.
Ordinary backup mode: The system attempts to set up an ordinary backup CR-LSP over a new explicit path, only when the primary CR-LSP fails. No additional bandwidth is needed in ordinary backup mode. In the case that the primary CR-LSP fails, this mode provides a traffic switchover slower than that of the hot-standby mode.
Best-effort path mode: When both the primary and backup CR-LSP fail, the system establishes a best-effort path. There are few constraints on the establishment of best-effort path; therefore, it is easy to set up. In best-effort path mode, packet loss is decreased, and certain QoS requirements may not be guaranteed.

Prerequisites

A tunnel ID has been configured by running the mpls te tunnel-id command.

Precautions

After tunnel backup is enabled, the route storing function is automatically enabled, regardless of whether the mpls te record-route command is run.

Tunnel backup and the function configured by running the mpls te resv-style ff command are mutually exclusive.

The mpls te backup ordinary command and the mpls te backup ordinary best-effort command cannot be configured together; otherwise, the previous configuration overrides the later one.

After initiating the dynamic bandwidth function for a hot-standby CR-LSP, the hot-standby CR-LSP does not occupy any bandwidth when bearing no traffic. If the primary CR-LSP fails, the system re-establishes a hot-standby CR-LSP with the expected bandwidth according to the Make-Before-Break mechanism. The new hot-standby CR-LSP now transmits traffic. The system then deletes the hot-standby CR-LSP with the bandwidth being 0 bit/s.

Example

# Enable hot standby for the current CR-LSP.

<HUAWEI> system-view
[HUAWEI] interface tunnel 1
[HUAWEI-Tunnel1] tunnel-protocol mpls te
[HUAWEI-Tunnel1] destination 2.2.2.2
[HUAWEI-Tunnel1] mpls te tunnel-id 100
[HUAWEI-Tunnel1] mpls te backup hot-standby
[HUAWEI-Tunnel1] mpls te commit