algorithms use tables that contain the "best" routes to every destination in the system. Metrics is used to determine the "best" routes. In small networks, a common metric would be to count how many gateways a message would need to traverse to reach the destination. More complex networks would choose a metric that represents the time delay, cost of sending, or some other quantity. The main point is that the metric represents the "cost" for individual hops. Each gateway periodically exchanges information in update messages that describes the routing database in that entity. MESSAGE FORMATS:Since RIP is a User Datagram Protocol (UDP) based protocol, it must send and receive datagrams on UDP port number 520. The packet format is as shown below: 0 1 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | command (1) | version (1) | must be zero (2) | +---------------+---------------+-------------------------------+ | address family identifier (2) | must be zero (2) | +-------------------------------+-------------------------------+ | IP address (4) | +---------------------------------------------------------------+ | must be zero (4) | +---------------------------------------------------------------+ | must be zero (4) | +---------------------------------------------------------------+ | metric (4) | +---------------------------------------------------------------+ . .The following commands can be implemented in version 1 of the protocol:* 1 - request: request for all or part of its routing table* 2 - respo...
