Enhancement: FRR is missing PIM-DM (dense mode) multicast mode

[apwiggins]

Enhancement: FRR is missing PIM-DM (dense mode) multicast mode

FRR currently has PIM-SM and PIM-SSM, but lacks PIM-DM (dense mode). It would help for feature parity with router vendors (Cisco, Juniper, etc) to have this multicast mode added. There are use cases (e.g. mobile) where maintaining a fixed multicast tree structure is not effective or advisable. There would be good benefit to having an integrated PIM-DM mode in FRR for unified multicast configuration of a router rather than configuring and running a separate PIM-DM multicast daemon.

• RFC 3973: Protocol Independent Multicast - Dense Mode (PIM-DM): Protocol Specification (Revised)
  -- https://tools.ietf.org/html/rfc3973

• Reference implementation:
  -- http://antc.uoregon.edu/PIMDM/pimd-dense.html
  -- http://antc.uoregon.edu/PIMDM/pimd-dense.tar.gz

Components

[pimd]

[eqvinox]

Added to feature request page at
https://github.com/FRRouting/frr/wiki/Feature-Requests

Note that there's currently noone working on it since interest has been pretty low...

[troglobit]

Since there doesn't seem to be any useful Open Source PIM-DM implementation today, I've decided to adopt Kurt's old implementation and restore it to build and run on modern systems; Linux and *BSD -- https://github.com/troglobit/pimd-dense/

Since I'm also the maintainer for the old USC pimd (as well as mrouted), I'll do my best to sync the codebases, fixing bugs in shared code etc.

Just mentioning it here since anyone who do a FRR/Quagga "qpimdd" may need a reference implementation.

[donaldsharp]

@troglobit why not update the pim implementation in FRR? We have lots of users and more than a few regular maintainers of the pim code here.

[troglobit]

@donaldsharp frankly, we've had problems using FRR on our embedded systems, mostly because of massive cross-compiling issues. The changes to the FRR build system have been hard to keep up with, so currently we run an older version.