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 speci-
     fied by the DDN Network Information Center.

     Each line is of the following format:

          protocol number aliases ...

     where the fields are delimited  by  spaces  or  tabs.  Empty
     lines  and  lines starting with a hash mark (#) are ignored.
     Remainder of lines are also ignored from the occurrence of a
     hash mark.

     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  net-
     workwide   naming   service   like   Yellow   Pages/NIS   or
     BIND/Hesoid.

FILES

     /etc/protocols
          The protocols definition file.

SEE ALSO

     getprotoent(3)

     Guide to Yellow Pages Service

     Guide to BIND/Hesiod Service