What is the ICMP protocol?
Rimscout continuously collects certain network data and performs tests to better diagnose problems in the network and to measure the availability and performance of stations, e.g. routers or providers. This requires the ICMP protocol. However, during our network assessments, we encounter environments where ICMP is restricted or even completely blocked.
To understand the importance of ICMP, we will first look at the various other transport protocols. The TCP protocol is the backbone of the Internet Protocol and contains essential functions required for smooth communication between devices. ICMP packets play a crucial role in this. They often work in the background to keep traffic flowing. UDP, on the other hand, is used not only for DNS queries, but also for the transmission of audio and video packets. Packet loss can easily occur here. However, during assessment or monitoring, the assessor or administrator must be informed of the packet loss with a meaningful error message.
This is where ICMP comes into play. It works at the lower level of the IP stack to exchange status and error messages between devices on the network, reporting unreachable destinations or network congestion. In addition, ICMP interacts with the previously mentioned TCP and UDP transport protocols by sending error messages for data packets that have not been delivered.