protocols(5) - Linux man page

Name

protocols - the 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 networkwide naming service like Yellow Pages/NIS or BIND/Hesiod.

Files

/etc/protocols
The protocols definition file.

See Also

getprotoent(3)

Guide to Yellow Pages Service

Guide to BIND/Hesiod Service

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

Referenced By

flowgrep(8), getsockopt(2), libbind-irs.conf(5), services(5), shorewall-accounting(5), shorewall-blacklist(5), shorewall-masq(5), snmpnetstat(1), socket(2)