Support for option 121 (classless-static-routes) is needed

name: Feature request
about: Support classless-static-routes (option 121)

Some initial questions

• While routes can be hand-mangled into the correct order and then expressed as a string of hex bytes, this is onerous for DHCP administrations and error-prone. A plugin could be done to support this option.

Is your feature request related to a problem? Please describe. In a complex enterprise mesh VPN with redundant IPsec connectivity, the DHCP server might need to provide hints as to that topology. This feature would make it easier to provide CIDR routes to the various islands in the mesh.

Describe the solution you'd like A simpler notation expressing [subnet, next-hop]* where the plugin figures out the appropriate encoding of the prefix, the significant octets of the subnet, and the 4 octets of next-hop router.

Describe alternatives you've considered In cases where a front-end (such as a Netconf/YANG proxy) synthesizes a Kea configuration, it could do the encoding previously described, but developers would probably appreciate being able to inspect and easily validate the intermediate Kea config that the front-end generated.

Additional context An example of having to encode this is currently done for ISC-DHCP in OpenWRT when converting UCI to ISC-DHCP config.

Funding its development If given examples of another plugin that might serve as a suitable homologue, I'd be willing to try to write such a plugin myself.

Participating in development Yes, I'm willing to participate in all phases.

Contacting you philipp@redfish-solutions.com or philipp64 on oftc.net or libera.chat.