protocols(5) — Linux manual page

protocols(5)               File Formats Manual              protocols(5)

NAME

       protocols - protocols definition file

DESCRIPTION

       This file is a plain ASCII file, describing the various DARPA
       internet protocols that are available from the TCP/IP subsystem.
       It should be consulted instead of using the numbers in the ARPA
       include files, or, even worse, just guessing them.  These numbers
       will occur in the protocol field of any IP header.

       Keep this file untouched since changes would result in incorrect
       IP packages.  Protocol numbers and names are specified by the
       IANA (Internet Assigned Numbers Authority).

       Each line is of the following format:

              protocol number aliases ...

       where the fields are delimited by spaces or tabs.  Empty lines
       are ignored.  If a line contains a hash mark (#), the hash mark
       and the part of the line following it are ignored.

       The field descriptions are:

       protocol
              the native name for the protocol.  For example ip, tcp, or
              udp.

       number the official number for this protocol as it will appear
              within the IP header.

       aliases
              optional aliases for the protocol.

       This file might be distributed over a network using a network-
       wide naming service like Yellow Pages/NIS or BIND/Hesiod.

FILES

       /etc/protocols
              The protocols definition file.

SEE ALSO

       getprotoent(3)

       ⟨http://www.iana.org/assignments/protocol-numbers⟩

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Linux man-pages 6.9.1          2024-05-02                   protocols(5)

Pages that refer to this page: getsockopt(2), socket(2), getprotoent(3), getprotoent_r(3), services(5)

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