RIP Protocol troubleshooting

RIP Protocol troubleshooting 01. What protocol does RIP transmit information and what mechanism is used to calculate the optimal route? RIP updates route information based on UDP port 520 using the BELLMEN-FORD algorithm. The basic principle is to follow the minimum hop count principle. Therefore, the route table path is not necessarily the optimal path. 02. In a non-broadcast environment, what commands can be used to send and receive route information based on unicast? R12001 uses the broadcast address 255.255.255.255.255 to send information on the INTERFACE. In non-broadcast environments, it mainly sets the PASS-INTERFACE on the INTERFACE or rejects the broadcast address through the access list. Generally, only the neighbor can be manually specified. In the routing mode, the neighbor ip-address is used. 03. Why is the maximum number of hops supported by RIP Based on 15 hops and 16 hops inaccessible? In the RIP message format, the measured value is 32 bits, that is, the maximum RIP value can be 2 to the power of 32 hops, and the RIP update period is 30 s, if there is such a large network, how slow its convergence is, that is, the reason why RIP is only suitable for small networks. 04. Why does RIP not support discontinuous subnets? How does it work? The example shows that RIP has a class protocol and does not support non-consecutive subnets. By default, it will automatically summarize at the main network boundary. The following example describes the rules for receiving and sending RIP messages. 192. 168.1.1/24---r1-------10.10.1/30---------------R2---192.168.1.3/24 configure the RIP Protocol sending rule between R1 and R2: If the sent Route IP address and the sending interface are in the same master network and have the same subnet mask, if the subnet mask is not the same, it is discarded. If the IP address of the route to be sent is not in the same master network as the sending interface, the route is automatically summarized at the boundary and then forwarded. Receiving rule: if the received Route IP address cannot be obtained from other interfaces, add it to the routing table. If the received Route IP address information is obtained from other interfaces, deny the route information. According to the sending and receiving rules, we can get that 192.168.1.1/24 is summarized into 192.168.1.0/24 at R1, and in R2, there is an interface 192.168.1.3/24, therefore, the summary information sent from R1 is discarded. Therefore, RIP does not support discontinuous subnets.