Brocade Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide (Supporting R05.6.00) - Manual (Page 155)

Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide 131
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Setting up signaled LSPs
1
Syntax: [no] secondary-path path name
Issuing the secondary-path command enters the secondary path configuration level. From this
level, the user can specify that this path is to operate in hot standby mode.
Example
Brocade(config-mpls-lsp-sec-path)# standby
Syntax: [no] standby
Once the LSP is enabled, both the primary and hot-standby paths are activated, although packets
are directed over only the primary path.
NOTE
At the secondary path level, the user can configure separate values for the following parameters:
Class of Service (CoS), setup and hold priority, bandwidth allocations, and inclusion or exclusion of
interfaces in administrative groups. When the user does not configure these parameters at the
secondary path level, the secondary path uses the default values for these parameters.
Configuring path selection
The user can exercise further control over the paths used by an LSP by setting the select mode and
by specifying a preferred path using the select-path command as described below.
By default, an LSP with primary and secondary paths configured immediately uses the primary
path. When the primary path fails, a secondary (redundant) path is used. When the primary path
comes back up, traffic reverts to the primary path and the secondary (redundant) path returns to a
back-up state. However, path selection can be configured to operate in any of the following three
modes:
• auto select mode – This is the default mode of the router and no special configuration is
required. When this mode is operating, the router always tries to use the primary path to carry
traffic when the primary path has stayed operating in the working state for at least the amount
of time specified in revert-timer configuration command. When no revert-timer is configured
for the LSP, a value of zero second is used which causes immediate switching of the path.
• manual select mode – In this mode, traffic is switched to a user-specified path after the
selected path has stayed operating in the working state for at least the amount of time
specified in revert-timer configuration. In manual select mode, traffic stays on the selected
path as long as the path remains in working condition and only switches to an alternative path,
such as the primary path, when the selected path experiences a failure. Once the selected
path comes back into working condition for the amount of time specified by the revert-timer
configuration, traffic is switched back to it.
When an LSP is configured in manual select path mode with at least one other hot standby
secondary path, the operation is as follows: when the selected path goes down, the system
tries to bring up one hot standby secondary path to protect the primary path, but when the
selected path is up, system brings down the hot standby secondary path since the selected
path is already serving as a hot standby for the primary path.