iptos(4)						     Kernel Interfaces Manual							  iptos(4)

NAME

       iptos - Defines the IP Type Of Service (TOS) for FTP and Telnet

SYNOPSIS

       /etc/iptos

DESCRIPTION

       The /etc/iptos file configures the Type Of Service (TOS) of the Internet Protocol (IP) used by FTP and Telnet.

       The TOS field in the Internet datagram is to specify how the datagram should be handled.  It is a mechanism to allow control information to
       have precedence over data.

       Generally, protocols that are involved in direct interaction with a human should select low delay, while data transfers that involve  large
       blocks of data need high throughput.  Finally, high reliability is most important for datagram-based Internet management functions.

       In  the	Tru64 UNIX operating system, the ftp and telnet applications and the ftpd and telnetd daemons allow the configuring of TOS values.
       These applications check to see if the /etc/iptos file exists; if the file exists, the applications obtain the TOS value from the file  and
       use  that  value  to set the TOS field.	If the /etc/iptos file does not exist, the applications default to the following TOS values recom-
       mended by RFC1060: Low delay High throughput Low delay

       Users who want to configure their own TOS values for the TOS field should provide the /etc/iptos file.

									  Note
	    Most IP routers do not differentiate based on TOS, and therefore providing values other than the default would have  no  affect.   You
	    should not change the default values for FTP and Telnet.

       Each entry should consist of a single line of the form:

       Application  Proto  TOS-bits  aliases

       The  entry fields contain the following information: The name of an application TOS entry.  The protocol name for which the entry is appro-
       priate.	The TOS value to be set for the entry.	A list of aliases that exist for the entry.

       Items on an entry line are separated by any number of blanks, tabs, or combination of blanks and tabs.  A number sign  (#)  indicates  that
       the rest of the line is a comment and is not interpreted by routines that search the file.  Blank lines in the file are ignored.

       Valid TOS entry names are ftp-control and ftp-data for FTP and telnet for Telnet.

       The  TOS  value for the entry should be one of the following hexadecimal numbers, corresponding to TOS bits: Low delay High throughput High
       reliability

       If you need to disable the use of TOS bits, because you are having troubling communicating with a TCP/IP host that doe not conform entirely
       with the IP specification, you can disable the TOS bits by using the the following settings in the /etc/iptos file:

       # # Format of this file: # Application	Proto  TOS-bits       aliases #

       ftp-control     tcp    0x0 ftp-data	   tcp	  0x0 telnet		 tcp	0x0

EXAMPLES

       The following example shows typical entries in the /etc/iptos file:

       # # Format of this file: # Application	Proto  TOS-bits       aliases #

       ftp-control     tcp    0x10 ftp-data	    tcp    0x08 telnet		   tcp	  0x10

RELATED INFORMATION

       RFC1060, ftp(1), telnet(1), ftpd(8), telnetd(8) delim off

																	  iptos(4)