The routed path for an RSVP-TE LSP can be described by a configured sequence of the LSRs and/or subnets traversed by the path. Each defined LSR or subnet represents an ERO subobject. Up to 64 subobjects can be added to each path name. LSRs and/or subnets can be either included or excluded.
| path_name | Specifies the path to which the IP address is added. |
| include | Specifies an LSR or subnet to be included in the path calculation. |
| ipNetmask | Specifies an IP prefix. |
| strict | Specifies that the subobject must be topologically adjacent to the previous subobject in the ERO list. |
| loose | Specifies that the subobject need not be topologically adjacent to the previous subobject in the ERO list. |
| exclude | Specifies a subnet to be excluded in the path calculation. |
| number | Specifies the LSR path order. |
The order value defaults to 100 if the path has no EROs configured or a value 100 more than the highest order number configured for the path.
This command adds an IP address to the Explicit Route Object (ERO) for the specified path name. The RSVP-TE routed path may be described by a configured sequence of the LSRs and/or subnets that the path traverses. Each defined LSR or subnet represents an ERO subobject. Up to 64 subobjects can be added to each path name. The ERO keyword identifies an LSR using an IP prefix, which may represent an LSR's Router ID, loopback address, or direct router interface. Each IP prefix is included in the ERO as an IPv4 subobject.
If the ERO is specified as strict, the strict subobject must be topologically adjacent1 to the previous subobject as listed in the ERO. If the ERO is specified as loose, the loose subobject is not required to be topologically adjacent to the previous subobject as listed in the ERO. If the specified IP prefix matches the OSPF router ID or a configured loopback IP address, the ERO must be configured as loose.
The LSR path order is optionally specified using the order keyword. The order number parameter is an integer value from 1 to 65535. IP prefixes with a lower number are sequenced before IP prefixes with a higher number. Thus, the LSP path follows the configured path of IP prefixes with a number value from low to high. If the order keyword is not specified, the number value for the LSR defaults to a value equal to the current highest number value plus 100. If the list of IP prefixes added to the path does not reflect an actual path through the network topology, the path message is returned with an error from a downstream LSR and the LSP is not established.
The order of a configured subobject cannot be changed. The ERO subobject must be deleted and re-added with a different order. If a subobject is added to or deleted from the ERO while the associated LSP is established, the path is torn down and is re-signaled using the new ERO. Duplicate ERO subobjects are not allowed.
Defining an ERO for the path is optional. If no ERO is configured, the path is signaled along the best available path and the ERO is not included in the path message. When the last subobject in the ERO of the path message is reached and the egress IP node of the path has not been reached, the remaining path to the egress node is signaled along the best available path. If the next subobject in the ERO is loose, the best available path to the next subobject is chosen. Configuring EROs could lead an LSP to take an undesirable path through the network, so care should be taken when specifying EROs.
The following example adds the IP interface address 197.57.30.7/24 as a loose ERO to the path sydney-bypass:
configure mpls rsvp-te path sydney-bypass add ero 197.57.30.7/24 loose
This command was first available in ExtremeXOS 11.6.
The include and exclude options were added in ExtremeXOS 15.7. "Include" was the previous default behavior.
This command is available only on the platforms that support MPLS (Multiprotocol Label Switching) as described in the ExtremeXOS 22.4 Feature License Requirements document.
Print
this page
Email this topic
Feedback
View PDF
Download EPUB