0777: Internet Control Message Protocol.
The Internet Protocol (IP)  is used for host-to-host datagram service in a system of interconnected networks called the Catenet . The network connecting devices are called Gateways. These gateways communicate between themselves for control purposes via a Gateway to Gateway Protocol (GGP) [3,4]. Occasionally a gateway or destination host will communicate with a source host, for example, to report an error in datagram processing. For such purposes this protocol, the Internet Control Message Protocol (ICMP), is used. ICMP, uses the basic support of IP as if it were a higher level protocol, however, ICMP is actually an integral part of IP, and must be implemented by every IP module.
Format TXT=19407 bytes
Date April 1981
Keyphrases datagrams destination message RFC