What is RIP (Routing Information Protocol)?
Answer
RIP (Routing Information Protocol) is one of the oldest distance-vector routing protocols, using hop count as its sole metric — the number of routers a packet must pass through to reach the destination. Maximum hop count is 15; 16 is considered unreachable. RIP is simple to configure but has significant limitations: slow convergence (uses periodic updates every 30 seconds), maximum network diameter of 15 hops, no support for VLSM in RIPv1, and susceptibility to routing loops (mitigated by split horizon, route poisoning, and holddown timers). RIPv1: classful, broadcasts updates, no authentication. RIPv2: classless (VLSM support), multicasts updates (224.0.0.9), supports authentication. RIPng: for IPv6. RIP is rarely used in production networks today — it has been replaced by OSPF and EIGRP for most enterprise deployments. It remains useful only in very small, simple networks or as a learning tool.