route-next-hop-policy
config>router
Supported on all 7210 SAS platforms as described in this document
Commands in this context configure route next-hop policies.
abort
config>router>route-next-hop-policy
Supported on all 7210 SAS platforms as described in this document
This command discards the changes that have been made to route next-hop templates during the current session.
begin
config>router>route-next-hop-policy
Supported on all 7210 SAS platforms as described in this document
Commands in this context edit route next-hop templates. Use the commit command to save edits made during the current session. Use the abort command to discard edits made during the current session.
commit
config>router>route-next-hop-policy
Supported on all 7210 SAS platforms as described in this document
This command saves the changes that have been made to route next-hop templates during the current session.
[no] template name
config>router>route-next-hop-policy
Supported on all 7210 SAS platforms as described in this document
This command creates a template to configure the attributes of a Loop-Free Alternate (LFA) Shortest Path First (SPF) policy. An LFA SPF policy allows the user to apply specific criteria, such as admin group and SRLG constraints, to the selection of a LFA backup next-hop for a subset of prefixes which resolve to a specific primary next-hop.
The user first creates a route next-hop policy template under the global router context and then applies it to a specific OSPF or ISIS interface in the global routing instance.
A policy template can be used in both IS-IS and OSPF to apply the specific criteria to prefixes protected by LFA. Each instance of IS-IS or OSPF can apply the same policy template to one or more interfaces.
The commands within the route next-hop policy template use the begin-commit-abort model.
The following are the steps needed to create and modify the template.
To create a template, the user enters the name of the new template directly under the route-next-hop-policy context.
To delete a template which is not in use, the user enters the no form of the template command under the route-next-hop-policy context.
The user enters the editing mode by executing the begin command under the route-next-hop-policy context. The user can then edit and change any number of route next-hop policy templates. However, the parameter value will still be stored temporarily in the template module until the commit command is executed under the route-next-hop-policy context. Any temporary parameter changes will be lost if the user enters the abort command before the commit command.
The user is allowed to create or delete a template instantly when in the editing mode without the need to enter the commit command. Also, if the abort command is executed, it will have no effect on the prior deletion or creation of a template.
When the commit command is executed, IS-IS or OSPF will reevaluate the templates. If there are any net changes, ISIS or OSPF will schedule a new LFA SPF to recompute the LFA next-hop for the prefixes associated with these templates.
The no form of this command deletes the specified template.
Specifies the name of the template, up to 32 characters maximum.
description description-string
no description
config>router>route-next-hop-policy>template
Supported on all 7210 SAS platforms as described in this document
This command is used to configure the description of the next-hop template.
Specifies the description of the next-hop template, up to 80 characters maximum.
[no] exclude-group ip-admin-group-name
config>router>route-next-hop-policy>template
Supported on all 7210 SAS platforms as described in this document
This command prunes all links belonging to the specified admin group before making the LFA backup next-hop selection for a prefix.
If the same group name is part of both include-group and exclude-group configurations, the exclude-group configuration takes precedence. It other words, the exclude-group statement can be viewed as having an implicit preference value of 0.
The admin group criteria are applied before running the LFA next-hop selection algorithm.
The no form of this command deletes the admin group exclusion constraint from the route next-hop policy template.
Specifies the name of the admin group to be excluded, up to 32 characters maximum.
include-group ip-admin-group-name [pref preferences]
no include-group ip-admin-group-name
config>router>route-next-hop-policy>template
Supported on all 7210 SAS platforms as described in this document
This command instructs the LFA SPF selection algorithm to pick up a subset of LFA next-hops among the links which belong to one or more of the specified admin groups. A link which does not belong to at least one of the admin groups is excluded. However, a link can still be selected if it belongs to one of the groups in an include-group configuration but also belongs to other groups which are not part of any include-group configuration in the route next-hop policy.
The pref option is used to provide a relative preference for the admin group to select. A lower preference value means that LFA SPF will first attempt to select an LFA backup next-hop which is a member of the corresponding admin group. If none is found, then the admin group with the next higher preference value is evaluated. If no preference is configured for a specific admin group name, then it is supposed to be the least preferred, or numerically the highest preference value.
When evaluating multiple include-group configurations within the same preference, any link which belongs to one or more of the included admin groups can be selected as an LFA next-hop. There is no relative preference based on how many of those included admin groups the link is a member of.
If the same group name is part of both include-group and exclude-group configurations, the exclude-group configuration takes precedence. It other words, the exclude-group statement can be viewed as having an implicit preference value of 0.
The admin group criteria are applied before running the LFA next-hop selection algorithm.
The no form of this command deletes the admin group constraint from the route next-hop policy template.
Specifies the name of the admin group to be included, up to 32 characters maximum.
Specifies the relative preference of a group, with 1 corresponding to the highest preference and 255 corresponding to the lowest preference.
nh-type ip
no nh-type
config>router>route-next-hop-policy>template
Supported on all 7210 SAS platforms as described in this document
This command configures the next-hop type for the route next-hop policy template.
The user can select IP backup next-hop.
When the route next-hop policy template is applied to an IP interface, all prefixes using this interface as a primary next-hop will follow the next-hop type preference specified in the template.
The no form of this command deletes the next-hop type constraint from the route next-hop policy template.
Specifies that IP backup next-hop is preferred.
protection-type {link | node}
no protection-type
config>router>route-next-hop-policy>template
Supported on all 7210 SAS platforms as described in this document
This command configures the protection type for the route next-hop policy template.
The user can select if link protection or node protection is preferred in the selection of a LFA next-hop for all IP prefixes and LDP FEC prefixes to which a route next-hop policy template is applied. The default in SR OS implementation is node protection. The implementation will fall back to the other type if no LFA next-hop of the preferred type is found.
When the route next-hop policy template is applied to an IP interface, all prefixes using this interface as a primary next-hop will follow the protection type preference specified in the template.
The no form of this command deletes the protection type constraint from the route next-hop policy template.
Specifies that link protection is preferred.
Specifies that node protection is preferred.
[no] srlg-enable
config>router>route-next-hop-policy>template
Supported on all 7210 SAS platforms as described in this document
This command configures the SRLG constraint for the route next-hop policy template.
When this command is applied to a prefix, the LFA SPF will attempt to select an LFA next-hop from the computed ones, which uses an outgoing interface that does not participate in any of the SLRGs of the outgoing interface used by the primary next-hop.
The SRLG criterion is applied before running the LFA next-hop selection algorithm.
The no form of this command deletes the SRLG constraint from the route next-hop policy template.