The global config>router>mpls>admin-group-frr command is used to enable admin-group constraints when associating a manual or dynamic bypass LSP with the primary LSP path at a PLR node.
When the user enables this command, each PLR node reads the admin-group constraints in the FAST_REROUTE object included in the Path message of the LSP primary path. If the object is not included, the PLR reads the admin-group constraints from the Session Attribute object in the Path message.
If the PLR is also the ingress LER for the LSP primary path, the PLR uses the admin-group constraint from the LSP or path level configurations.
Whether the PLR node is also the ingress LER or just an LSR for the protected LSP primary path, the outcome of the ingress LER configuration dictates the behavior of the PLR node. The following table summarizes the bypass LSP admin-group behavior.
Ingress LER configuration |
Session attribute |
FRR object |
Bypass LSP at PLR (LER/LSF) follows admin-group constraints |
|
|---|---|---|---|---|
1 |
frr-object lsp>no propagate-admin-group lsp>frr>propagate-admin-group |
Admin color constraints not sent |
Admin color constraints sent |
Yes |
2 |
frr-object lsp>propagate-admin-group lsp>frr>propagate-admin-group |
Admin color constraints sent |
Admin color constraints sent |
Yes |
3 |
frr-object lsp>propagate-admin-group lsp>frr>no propagate-admin-group |
Admin color constraints sent |
Admin color constraints not sent |
No |
4 |
no frr-object lsp>propagate-admin-group lsp>frr>propagate-admin-group |
Admin color constraints sent |
Not present |
Yes |
5 |
no frr-object lsp>no propagate-admin-group lsp>frr>propagate-admin-group |
Admin color constraints not sent |
Not present |
No |
6 |
no frr-object lsp>propagate-admin-group lsp>frr>no propagate-admin-group |
Admin color constraints sent |
Not present |
Yes |
Next, the PLR node uses the admin-group constraints and other constraints, such as hop-limit and SRLG, to select a manual or dynamic bypass among those that are already in use.
If none of the manual or dynamic bypass LSPs satisfy the admin-group constraints and other constraints, the PLR node requests the CSPF for the path that merges closest to the protected link or node and includes or excludes the specified admin-group IDs.
Modifying the configuration of the config>router>mpls>admin-group-frr command does not affect existing bypass associations. The change only applies to new attempts to find a valid bypass.