Sunday, November 29, 2009
RIP Protocol and Floating Static Routes
Today I read up on topics related to the two different RIP versions 1 and 2 which was mostly review for me. There was some good stuff such as using both RIPv1 and RIPv2 on a network which i of course created a lab for. I also went over topics related to classful and classless routing over a network and how routing updates are summarized over Dis-contiguous or over different major classful networks. It was a good read and confirmed my suspicion that you can subnet within a classful network using RIPv1 as long as that subnet number is consistent throughout that network. However the network will still be summarized to a /16 when crossing major network boundaries.
I finished up today by learning about Floating Static Routes which was A LOT simpler then I imagined it to be. A floating static route is primarily used when a dynamic routing protocol fails or when you have a WAN link fail and would like to have an automatic fail-over route say through anISDN/DSL backup connection. A floating static route is configured by setting the administrative distance (AD) on a static route higher than the dynamic protocol (AD). By doing this the static route "floats" above the dynamic protocol since best routes when using mutli protocols uses AD to determine the best protocol to use. By default a static route has an AD of either 0 or 1 depending on the configuration. The higher the AD the less likely it is to be used over another protocol as indicated in the picture above.