tcp(ADMN)

tcp -- TCP start/stop script

Syntax

/etc/tcp start

/etc/tcp stop

/etc/tcp shutdown

Description

/etc/tcp starts or stops the STREAMS TCP software. The tcp command is typically linked to the rc2 and rc0 scripts to start and stop TCP/IP automatically when changing machine states. See rc0(ADM) and rc2(ADM) for further information. You can also invoke the tcp command manually. The following describes the behavior of the tcp command when run with its various options.

start option

When run with the start option, the tcp command checks to see if the machine is at single user or multiuser mode.

If the machine is at single user mode, the tcp command does only a partial startup of TCP/IP which consists of running ifconfig(ADMN) to configure the network interfaces with their IP addresses. This partial startup permits root to execute network functions (such as ftp and telnet) with machines on the same subnet. In single user mode, the tcp command starts no other default daemons (such as inetd, snmpd, and routed). Therefore, no network functions requiring the routing of packets to subnets not directly connected to the local machine are allowed.

If the machine is at multiuser mode, the tcp command does the following complete startup of TCP/IP:

runs ifconfig(ADMN) to configure the network interfaces with their IP addresses
starts the following daemons (by default and if conditional statements are true): gated, inetd, irdd, lpd, named, pppd, routed, snmpd, strerr, syslogd, ntpd

stop option

When run with the stop option, the tcp command brings TCP/IP from a complete startup state to the partial startup state described under the start option. Because the TCP/IP protocol stack remains assembled and the interfaces remain configured, existing networking sessions (such as ftp and rlogin sessions) with remote machines will not be disconnected by the tcp stop operation. If a user or a timeout disconnects a session, the session cannot be be reconnected while TCP/IP is in the partial startup state. A benefit of tcp stop is that much of TCP/IP can be stopped and then restarted without doing a complete reboot.

shutdown option

When run with the shutdown option, the tcp command stops all network operations (any active connections are terminated).

/etc/tcp must be customized for a particular installation before it can be used. The following items must be edited:

Domain name: The environment variable DOMAIN must be set to the name of your domain.
Interface configuration: ifconfig commands must be used to set the internet address (and any other desired options) for each of your interfaces. The ifconfig line for the loopback interface should not require modification. See ifconfig(ADMN) for further information.

The following items may need to be edited:

PATH: The supplied path may require modification if commands run by /etc/tcp are in other directories.
PROCS: The PROCS variable contains a space-separated list of names of processes to kill when executing the stop function. If additional daemons are used, their names can be added to this list.
Daemons: The standard internetworking daemons are started at this point. Any additional daemons or other commands may be included in this section. Any of the standard daemons that are not desired may be removed or commented out.

tcp(ADMN)

Syntax

Description

See also