The routing information protocol, which is a very common and important protocol. If you want to learn the routing protocol well, you must understand the concept of this routing information protocol. Now let's take a detailed analysis. The routing information protocol was originally designed for Xerox PUP (PARC universal protocol). the routing information protocol was collectively referred to as "GWINFO" in the Xerox network system protocol in 1981 ", it was also defined as "RFC 1988" in 1058. the routing information protocol is easy to configure and works very well in small networks. However, in large networks, the routing information protocol is inefficient. As I said to myself, the routing information protocol will split your network. In large network environments, there are protocols that replace the routing information protocol 。
The routing information protocol has the following features:
◆ Open protocols are widely used and stable 。
◆ Suitable for small networks and easy to configure 。
◆ Distance vector routing protocols similar to routing information protocols are available for Novell and Appletalk software 。
◆ Internal Gateway Protocol (IGP)
◆ IP route information protocol updates are broadcast once every 30 seconds (the multicast addresses of all RIPv2 routers are 224.0.0.9 )。
◆ UDP (User Datagram Protocol) Port 520 。
◆ The manageable distance is 120 。
◆ A single measurement criterion is the number of computing hops (the limit is 15 and the count is infinite)
◆ Timer helps adjust performance:
Update timer-the frequency of Route updates 。
The IP route information protocol sends a complete route table every 30 seconds, depending on the Horizontal Split (IPX route information protocol sends the route table every 60 seconds )。
Illegal timer-the content that is not refreshed in the route update. the routing information protocol waits for 180 seconds, and then marks a route as illegal and immediately puts the route in a restrained timing state 。
Maintain timing and trigger updates-help with stable routing in Cisco magic. suppressing timing ensures that normal updates do not properly cause route loops. routers do not offer superior performance during a specific period of time. the suppression time of the routing information protocol is 180 seconds 。
Refresh timer-the route information protocol takes an additional 240 seconds before deleting the route from the route table 。
◆ Other stable functions that help route loops include:
Horizontal Split
Toxicity reversal
◆ Bellman-Ford Algorithm
◆ R12002 supports VLSM and automatic summarization 。