RIP is a relatively simple routing protocol. A RIP-enabled router receives routing information from RIP-enabled neighboring routers, and builds a routing table with the reachable IP address, hop count, and next hop. The main limitation of RIPv1 was a hop count limit of 15. RIPv2 was introduced a few years later; the hop count limit of 15 remained in order to maintain backward compatibility with RIPv1, but other features were added, such as support for multicasting and the ability to carry subnet information.