The Internet Control Message Protocol (ICMP) is a protocol that devices within a network use to communicate problems with data transmission. In this ICMP definition, one of the primary ways in which ICMP is used is to determine if data is getting to its destination and at the right time.
ICMP is a transport level protocol within TCP/IP which communicates information about network connectivity issues back to the source of the compromised transmission. It sends control messages such as destination network unreachable, source route failed, and source quench.
ICMP (Internet Control Message Protocol) is an error-reporting protocol network devices like routers use to generate error messages to the source IP address when network problems prevent delivery of IP packets. Any IP network device has the capability to send, receive or process ICMP messages.
ICMP (Internet Control Message Protocol) is a protocol that network devices (e.g. routers) use to generate error messages when network issues are preventing IP packets from getting through. The Internet Control Message Protocol is one of the fundamental systems that make the internet work.
ICMP uses the source IP address to send the error message to the source (originator) of the datagram. Five types of errors are handled: destination unreachable, source quench, time exceeded, parameter problems, and redirection (see figure1).
Internet Control Message Protocol (ICMP) Parameters
ICMP is a network-layer protocol. There is no TCP or UDP port number associated with ICMP packets as these numbers are associated with the transport layer above.
The Internet Control Message Protocol, or ICMP, has an entirely different function than TCP and UDP. Unlike these types, ICMP is not a traditional data packet protocol. ICMP is built specifically for testing networks with minimal overhead.
How to Enable ICMP (PING) through the Windows Firewall with Advanced Security using Group Policy
Firewall rules for ICMP (TCP/UDP port 7)
The only essential ICMP traffic you need to allow in and out of your firewall is Type 3 and Type 4. Everything else is either optional or should be blocked.
The standard ping command does not use TCP or UDP. It uses ICMP. To be more precise ICMP type 8 (echo message) and type 0 (echo reply message) are used. ICMP has no ports!
Traceroute is a network diagnostic tool used to track in real-time the pathway taken by a packet on an IP network from source to destination, reporting the IP addresses of all the routers it pinged in between. Traceroute also records the time taken for each hop the packet makes during its route to the destination.
TCP/IP, or Transmission Control Protocol/Internet Protocol, is a suite of communication protocols used to interconnect network devices on the internet. TCP/IP can also be used as a communications protocol in a private computer network (an intranet or extranet).
In the same way, messaging protocols are the rules, formats, and functions for messages sent between machines. Essentially, everyone has agreed on the types of information to include with data packets (i.e. like an address) and the way of formatting that information so everyone can read it.