The second method uses the MD5 algorithm to create a crypto checksum of a RIP packet and an authentication key of up to 16 characters. This method provides very little security, as it is possible to learn the authentication key by watching RIP packets. If this password does not match what is expected, the packet is discarded. The first method is a simple password in which an authentication key of up to 16 characters is included in the packet. RIP 2 packets also can contain one of two types of authentication methods that can be used to verify the validity of the supplied routing data. RIP 2 adds the ability to specify explicitly the network mask for each network in a packet. This assumption prevents subnets with different network masks from being included in RIP packets. It uses this assumption to calculate the network masks for all routes received. The RIP 1 protocol assumes that all subnetworks of a given network have the same network mask. Some of the most notable RIP 2 enhancements follow. The RIP version 2 protocol adds capabilities to RIP. The Check Point implementation of RIP 1 supports auto summarization this allows the router to aggregate and redistribute nonclassful routes in RIP 1. If bits outside the mask are set, it is assumed to be a host otherwise, it is assumed to be a subnet. If a received network or host is on the same natural network as the interface over which it was received, and that network is subnetted (the specified mask is more specific than the natural network mask), then the subnet mask is applied to the destination. RIP 1 derives the network mask of received networks and hosts from the network mask of the interface from which the packet was received. The maximal number of hops in a RIP network is 15 and the protocol treats anything equal to or greater than 16 as unreachable. Networks reachable through one other router are two hops, and so on. Directly connected networks have a metric of 1. The distance is expressed as an integer, the hop count metric. Each update contains paired values consisting of an IP network address and a distance to that network. Routers using RIP broadcast their routing tables on a periodic basis to other routers, whether or not the tables have changed. Other shortcomings of RIP are that it can create excessive network traffic if there are a large number of routes and that it has a slow convergence time and is less secure than other IGPs, such as OSPF. RIP uses only the number of hops between nodes to determine the cost of a route to a destination network and does not consider network congestion or link speed. The Routing Information Protocol (RIP) is one of the oldest, and still widely used, interior gateway protocols (IGP).

Rip direction and rip version