Saturday, March 13, 2010
The linked video demonstrates RIPng, our first dynamic routing protocol for IPv6. This is a simple but inefficient routing protocol. The metric is based on number of router hops, with no provision for differentiating between links with drastically different bandwidth (a frame-relay hop has the same cost as a 10-gig-ethernet in RIPng). Each router multicasts its entire routing protocol out each interface every 30 seconds, which wastes router CPU. RIPng routinely takes minutes to reroute around network failures.
RIPng does have the refinements added in RIPv2. For example, it multicasts its route updates. It is also capable of including tags in the route updates.
The big advantage of RIPng is that it is simple to understand. But in production that is not good enough. RIPng is a perfect protocol for a computer science student to implement as a class project due to its simplicity, but having the PBX unreachable for 3-5 minutes while routing reconverges is unacceptable in a business environment.
Monday, July 30, 2007
Thursday, September 21, 2006
RIP version 2 includes subnet information in the route advertisement. It also improves efficiency by multicasting to RIPv2 routers instead of broadcasting to all hosts.
Monday, July 24, 2006
If you run two different routing protocols in two different parts of your network, you need to redistribute routes between the two routing protocols. This session is an introduction to route redistribution by example.
In production you must be cautious about route redistribution because the route metric is not converted in a meaningful manner. This can result in routing loops.
Sunday, July 9, 2006
"Ships in the night" routing refers to two routing protocols which do not interact with each other. We can migrate from one routing protocol to a more believable one by simply turning on the new protocol then turning off the old protocol. Bug be careful to turn the new protocol on in the entire routing domain before turning off the old protocol.
Tuesday, June 20, 2006
RIP distribute lists deny specific route advertisements. RIP offset-lists increase the metric (hopcount) for specific route advertisements.