primary path-name
no primary
config>router>mpls>lsp
Supported on all 7210 SAS platforms as described in this document
This command configures a preferred path for the LSP. This command is optional only if the secondary path-name is included in the LSP definition. Only one primary path can be defined for an LSP.
Some of the attributes of the LSP, such as the bandwidth and hop-limit, can be optionally specified as the attributes of the primary path. The attributes specified in the primary path-name command override the LSP attributes.
The no form of this command deletes the association of this path-name from the LSP lsp-name. All configurations specific to this primary path, such as record, bandwidth, and hop limit, are deleted. The primary path must be first shut down to delete it.
The no form of this command results in no action except a warning message on the console indicating that the primary path is administratively up.
Specifies the case-sensitive alphanumeric name label for the LSP path, up to 32 characters.
[no] secondary path-name
config>router>mpls>lsp
Supported on all 7210 SAS platforms as described in this document
This command configures an alternative path that the LSP uses if the primary path is not available. This command is optional and is not required if the config router mpls lsp lsp-name primary path-name command is specified. After the switch over from the primary to the secondary, the 7210 SAS software continuously tries to revert to the primary path. The switch back to the primary path is based on the retry-timer interval.
Up to eight secondary paths can be specified. All the secondary paths are considered equal and the first available path is used. The 7210 SAS software does not switch back between secondary paths.
The 7210 SAS software starts the signaling of all non-standby secondary paths at the same time. Retry counters are maintained for each unsuccessful attempt. When the retry limit is reached on a path, the 7210 SAS software does not attempt to signal the path and administratively shuts down the path. The first successfully established path is made the active path for the LSP.
The no form of this command removes the association between this path-name and lsp-name. All specific configurations for this association are deleted. The secondary path must be shutdown first to delete it.
The no secondary path-name command results in no action except a warning message on the console indicating that the secondary path is administratively up.
Specifies the case-sensitive alphanumeric name label for the LSP path, up to 32 characters.
[no] adaptive
config>router>mpls>lsp>primary
config>router>mpls>lsp>secondary
Supported on all 7210 SAS platforms as described in this document
This command enables the MBB functionality for an LSP or a primary or secondary LSP path. When enabled for the LSP, an MBB operation is performed for primary path and all the secondary paths of the LSP.
adaptive
bandwidth rate-in-mbps
no bandwidth
config>router>mpls>lsp>primary
config>router>mpls>lsp>secondary
Supported on all 7210 SAS platforms as described in this document
This command specifies the amount of bandwidth to be reserved for the LSP path.
The no form of this command resets bandwidth parameters (no bandwidth is reserved).
no bandwidth
Specfies the amount of bandwidth reserved for the LSP path in Mb/s.
[no] exclude group-name [group-name...(up to 5 max)]
config>router>mpls>lsp>primary
config>router>mpls>lsp>secondary
Supported on all 7210 SAS platforms as described in this document
This command specifies the admin groups to be excluded when an LSP is set up. Up to 5 groups per operation can be specified, up to 32 maximum. The admin groups are defined in the config>router>mpls>admin-group context.
The no form of this command removes the exclude command.
no exclude
Specifies the existing group name to be excluded when an LSP is set up.
hop-limit number
no hop-limit
config>router>mpls>lsp>primary
config>router>mpls>lsp>secondary
Supported on all 7210 SAS platforms as described in this document
This command overrides the config router mpls lsp hop-limit command. This command specifies the total number of hops that an LSP traverses, including the ingress and egress routers.
This value can be changed dynamically for an LSP that is already set up with the following implications:
If the new value is less than the current hops of the established LSP, the LSP is brought down. MPLS then tries to re-establish the LSP within the new hop-limit number.
If the new value is equal or more than the current hops of the established LSP, the LSP is unaffected.
The no form of this command reverts to the values defined under the LSP definition using the config router mpls lsp lsp-name hop-limit command.
no hop-limit
Specifies the number of hops the LSP can traverse, expressed as an integer.
[no] path-preference value
config>router>mpls>lsp>secondary
Supported on all 7210 SAS platforms as described in this document
This command enables the use of path preference among configured standby secondary paths per LSP.
If all standby secondary paths have a default path-preference value, a non-standby secondary path remains an active path, while a standby secondary is available. A standby secondary path configured with highest priority (lowest path-preference value) must be made the active path when the primary is not in use. Path preference can be configured on standby secondary path.
The no form of this command reverts to the default value.
255
Specifies an alternate path for the LSP if the primary path is not available.
[no] record
config>router>mpls>lsp>primary
config>router>mpls>lsp>secondary
Supported on all 7210 SAS platforms as described in this document
This command enables recording of all the hops that an LSP path traverses. Enabling record increases the size of the PATH and RESV refresh messages for the LSP, because this information is carried end-to-end along the path of the LSP. The increase in control traffic per LSP may impact scalability.
The no form of this command disables the recording of all the hops for the specified LSP. There are no restrictions as to when the no command can be used.
The no form of this command also disables the record-label command.
record
[no] record-label
config>router>mpls>lsp>primary
config>router>mpls>lsp>secondary
Supported on all 7210 SAS platforms as described in this document
This command enables recording of all the labels at each node that an LSP path traverses. Enabling the record-label command also enables the record command, if it is not already enabled.
The no form of this command disables the recording of the hops that an LSP path traverses.
record-label
[no] srlg
config>router>mpls>lsp>secondary
Supported on all 7210 SAS platforms as described in this document
This command enables the use of the SRLG constraint in the computation of a secondary path for an LSP at the head-end LER.
When this feature is enabled, CSPF includes the SRLG constraint in the computation of the secondary LSP path. CSPF requires that the primary LSP already be established and in the up state, because the head-end LER needs the most current ERO computed by CSPF for the primary path. CSPF would return the list of SRLG groups along with the ERO during primary path CSPF computation. At a subsequent establishment of a secondary path with the SRLG constraint, the MPLS/RSVP task queries CSPF again, which provides the list of SLRG group numbers to be avoided. CSPF prunes all links with interfaces that belong to the same SRLGs as the interfaces included in the ERO of the primary path. If CSPF finds a path, the secondary is set up. If CSPF does not find a path, MPLS/RSVP keeps retrying the requests to CSPF.
If CSPF is not enabled on the LSP, a secondary path of that LSP that includes the SRLG constraint is shut down and a specific failure code indicates the exact reason for the failure in the show router mpls lsp path detail command output.
At initial primary LSP path establishment, if primary does not come up or primary is not configured, SRLG secondary is not signaled and is put in the down state. A specific failure code indicates the exact reason for the failure in show router mpls lsp path detail command output. However, if a non-SRLG secondary path was configured, such as a secondary path with the SRLG option disabled, the MPLS/RSVP task signals it and the LSP use it.
As soon as the primary path is configured and successfully established, MPLS/RSVP moves the LSP to the primary and signals all SRLG secondary paths.
Any time the primary path is reoptimized, has undergone MBB, or has come back up after being down, the MPLS/RSVP task checks with CSPF if the SRLG secondary should be resignaled. If MPLS/RSVP finds that the current secondary path is no longer SRLG disjoint, for example, it became ineligible and puts it on a delayed MBB immediately after the expiry of the retry timer. If MBB fails at the first try, the secondary path is torn down and the path is put on retry.
At the next opportunity that the primary path goes down, the LSP uses the path of an eligible SRLG secondary if it is in the up state. If all secondary eligible SLRG paths are in the down state, MPLS/RSVP uses a non SRLG secondary if configured and in the up state. If while the LSP is using a non SRLG secondary, an eligible SRLG secondary came back up, MPLS/RSVP does not switch the path of the LSP to it. As soon as primary is resignaled and comes up with a new SLRG list, MPLS/RSVP resignals the secondary using the new SRLG list.
A secondary path that becomes ineligible as a result of an update to the SRLG membership list of the primary path has the ineligibility status removed when any of the following occurs.
A successful MBB of the standby SRLG path, which makes it eligible again.
The standby path goes down. MPLS/RSVP puts the standby on retry at the expiry of the retry timer. If successful, it becomes eligible. If not successful after the retry-timer expires or the number of retries reaches the number configured under the retry-limit parameter, it is left down.
The primary path goes down. In this case, the ineligible secondary path is immediately torn down and is resignaled only when the primary comes back up with a new SRLG list.
When primary path of the LSP is set up and is operationally up, any subsequent changes to the SRLG group membership of an interface the primary path is using would not be considered until the next opportunity the primary path is resignaled. The primary path may be resignaled because of a failure or an MBB operation. MBB occurs as a result of a global revertive operation, a timer-based or manual reoptimization of the LSP path, or an operator change to any of the path constraints.
When an SRLG secondary path is set up and is operationally up, any subsequent changes to the SRLG group membership of an interface the secondary path is using would not be considered until the next opportunity the secondary path is resignaled. The secondary path is resignaled because of a failure, a resignaling of the primary path, or an MBB operation. MBB occurs as a result of a timer-based or manual reoptimization of the secondary path, or an operator change to any of the path constraints of the secondary path, including enabling or disabling the SRLG constraint.
Also, the user-configured include or exclude admin group statements for this secondary path are also checked together with the SRLG constraints by CSPF.
The no form of this command reverts to the default value.
no srlg
[no] standby
config>router>mpls>lsp>secondary
Supported on all 7210 SAS platforms as described in this document
The secondary path LSP is normally signaled when the primary path LSP fails. The standby command ensures that the secondary path LSP is signaled and maintained indefinitely in a hot-standby state. When the primary path is re-established, the traffic is switched back to the primary path LSP.
The no form of this command specifies that the secondary LSP is signaled when the primary path LSP fails.