In computer networking, the ICMP Internet Router Discovery Protocol (IRDP), also called the Internet Router Discovery Protocol,[1] is a protocol for computer hosts to discover the presence and location of routers on their IPv4 local area network. Router discovery is useful for accessing computer systems on other nonlocal area networks.[2] The IRDP is defined by the IETF RFC 1256 standard,[3] with the Internet Control Message Protocol (ICMP) upon which it is based defined in IETF RFC 792. IRDP eliminates the need to manually configure routing information.[1]