ICMP stands for Internet Control Message Protocol. ICMP types are used to send control messages from the source to destination computers. These messages can be used for troubleshooting, error reporting, and diagnostic purposes.
What is ICMP?
ICMP stands for Internet Control Message Protocol. This is a protocol that is used by routers to send error messages to hosts, and it’s also used by hosts to send error messages to routers. The ICMP protocol can also be used in the opposite direction, where it sends error messages back. Some common uses of this protocol include:
- A router receiving an echo request from a host, then sending back an echo reply
- A host sending an echo request when a router doesn’t respond in time
- Routers using link-local addresses instead of global ones
ICMP Types
ICMP types 10 and 11 are used to determine if a remote host is reachable and responding. ICMP type 12 is used to measure the round-trip time for a packet sent from one host to another. ICMP types 13 and 14 are used for network monitoring purposes, in particular ping.
ICMP Type 8 – Echo Request
This is an echo request sent by a user program running on the local system or device. This can be used by network administrators to troubleshoot networks and find out who is using how much bandwidth at what time of day or night.
Capture ICMP Type Echo Request Packets
You can capture ICMP type echo request packets using Wireshark.
- Open Wireshark and select “Capture” from the menu bar
- Click on “Interfaces” and select your interface from the list of available interfaces
- Click on “Start”, and then click “Start” again to start capturing packets on this interface
Capture ICMP Type Echo Reply Packets
[icmp type echo reply](https://en.wikipedia.org/wiki/ICMP_echo_requests)
[icmp type echo request](https://en.wikipedia.org/wiki/ICMP_echo_requests)
In this post, I have covered the basics of ICMP and its types. In my next blog post, I will be discussing more about ICMP as well as some real-world examples.