ODR or On-Demand Routing, is a Cisco proprietary routing protocol that I have a love-hate relationship with.
Simply put, I despise it due to its lack of configuration options, troubleshooting difficulties, and the fact that it uses CDP to transmit information which causes a huge pain on a switched network where the switch intercepts the CDP packets.
On the other hand, over something like a point to point link, I love how easy it is to set up. Just start the ODR process on the hub router with the single command "router odr" under config mode. The stub router will automatically get a default route and all networks attached to the stub router are automatically added to the routing table of the hub router. (Assuming CDP is enabled of course, which by default it is.)
Whats your opinion on ODR, if you've even ever heard of it (Seeing as it is proprietary and only suitable for very specific circumstances)?