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

COLOPHON

   This  page  is  part of release 4.09 of the Linux man-pages project.  A
   description of the project, information about reporting bugs,  and  the
   latest     version     of     this    page,    can    be    found    at
   https://www.kernel.org/doc/man-pages/.

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