Index for Section 4

Alphabetical listing for P

Bottom of page

protocols(4)
NAME
  protocols - Defines the Internet protocols used on the local host

SYNOPSIS
  /etc/protocols

DESCRIPTION
  The /etc/protocols file contains information about the known protocols used
  in the DARPA (Defense Advanced Research Projects Agency) Internet.  Each
  protocol is represented by a single line in the protocols file.  Each entry
  is of the form:

       Name Number Aliases

  The fields contain the following information:

  Name	    Official Internet protocol name.

  Number    Protocol number.

  Aliases   Unofficial names used for the protocol.

  Items on a line are separated by one or more spaces or tab characters.
  Comments begin with the # (number sign), and routines that search the
  protocols file do not interpret characters from the beginning of a comment
  to the end of the line.  A protocol name can contain any printable
  character except a field delimiter, newline character, or comment
  character.

  The lines in the file appear as follows:

       #
       # Internet (IP) protocols
       #
       ip      0    IP	       # internet protocol, pseudo protocol number
       icmp    1    ICMP       # internet control message protocol
       igmp    2    IGMP       # internet group management protocol
       ggp     3    GGP	       # gateway-gateway protocol
       tcp     6    TCP	       # transmission control protocol
       egp     8    EGP	       # exterior gateway protocol
       pup     12   PUP	       # PARC universal packet protocol
       udp     17   UDP	       # user datagram protocol
       hmp     20   HMP	       # host monitoring protocol
       rdp     27   RDP	       # "reliable datagram" protocol

RELATED INFORMATION
  Functions: endprotoent(3), getprotobyname(3), getprotobynumber(3),
  getprotoent(3), setprotoent(3)

Index for Section 4

Alphabetical listing for P

Top of page