Kernel Support Tools: rip2ad
A rip2ad Example
Consider the network in Figure 1. The Linux router named ritz needs to tell the corporate router, gate, about the local networks 192.168.0.0/24, 192.168.1.0/24, 192.168.2.0/24, and 192.168.3.0/24, which can be summarized as 192.168.0.0/22.
Figure 1 - rip2ad network example.
The problem could be solved by running RIP within the remote network, having ritz run RIP with static routes pointed towards the other LAN networks or having a static routing entry on gate; however, static routes might be prohibited by policy, which has the disadvantage of gate always further advertising the route even when the link is not available due to an outage.
Running a routing protocol daemon on ritz is overkill, but router, ritz, can use rip2ad to tell the corporate router, gate, about the networks without RIP having to run on itself, jos, or hild.