osf1 man page for protocols

protocols(4)						     Kernel Interfaces Manual						      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) Inter-
       net.  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: Official Internet protocol name.  Protocol number.  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) delim off

																      protocols(4)