ICMP
Technology & Computing abbreviation · Networking
| Stands for | Internet Control Message Protocol |
|---|---|
| Categories | Technology & Computing |
ICMP stands for Internet Control Message Protocol, a networking abbreviation.
Carries error reports and diagnostic messages for IP rather than user data, for example "destination unreachable" or "time exceeded". The ping utility sends ICMP echo requests and waits for echo replies, and traceroute relies on time-exceeded messages to map the path.
Example: Ping fails because the cloud firewall blocks ICMP, even though the web server is up.
Usage notes
Defined in RFC 792 in 1981; IPv6 uses its own version, ICMPv6, which also handles neighbor discovery. Blocking all ICMP is a common mistake because it breaks path MTU discovery, producing connections that hang on large transfers. ICMP floods and the historic "ping of death" were among the earliest denial-of-service techniques.
Related abbreviations
More networking abbreviations
- FTPS – FTP Secure
- GRE – Generic Routing Encapsulation
- HTTP – Hypertext Transfer Protocol
- HTTPS – Hypertext Transfer Protocol Secure
- IANA – Internet Assigned Numbers Authority
- ICANN – Internet Corporation for Assigned Names and Numbers
- IETF – Internet Engineering Task Force
- IMAP – Internet Message Access Protocol
- IP – Internet Protocol
- IPsec – Internet Protocol Security
- IPv4 – Internet Protocol version 4
- IPv6 – Internet Protocol version 6