Eliminate Redundant Paths with a One-Hop Zone

The following image illustrates an enterprise with four servers:

  • B1 and B2 serve producers at branch offices of an enterprise.
  • M serves consumers at the main office, which process the messages from the branches.
  • R serves consumers that record messages for archiving, auditing, and backup.

The goal is to forward messages from B1 and B2 to both M and R. The routing graph seems to contain a cycle—the path from B1 to M to B2 to R duplicates the route from B1 to R. However, since these routes belong to the one-hop zone Z2, it is impossible for messages to travel the longer path. Instead, this limitation results in the desired result—forwarding from B1 to M and R, and from B2 to M and R.