PROTOCOLS(5) File Formats Manual PROTOCOLS(5)

protocols — protocol name database

The protocols file contains information regarding the known protocols used in the Internet. For each protocol, a single line should be present with the following information:

official protocol name
protocol number
aliases

Items are separated by any number of blanks and/or tab characters.

A hash mark (‘#’) indicates the beginning of a comment; subsequent characters up to the end of the line are not interpreted by the routines which search the file.

Protocol names may contain any printable character other than a field delimiter, newline, or comment character.

/etc/protocols
 

getprotoent(3)

The protocols file format appeared in 4.2BSD.

A name server should be used instead of a static file. Lines in /etc/protocols are limited to BUFSIZ characters (currently 1024). Longer lines will be ignored.

March 3, 2019 OpenBSD 7.6