slip_manual_setup(7)					 Miscellaneous Information Manual				      slip_manual_setup(7)

NAME

       slip_manual_setup - Describes how to manually set up the Serial Line Internet Protocol (SLIP)

DESCRIPTION

       The Serial Line Internet Protocol (SLIP) is a protocol used to run IP over serial lines, including RS-232 cables connecting two systems and
       telephone circuits. Unlike Ethernet, a serial line provides a point-to-point connection between only two hosts. Like Ethernet, TCP/IP  com-
       mands (such as rlogin, ftp, and ping) can be run over the SLIP connection.

       Note  that  although you do not use a network interface with SLIP, you must have a network interface configured on your system for the net-
       work daemons (such as nfsd and rwhod) to run properly.  The network interface must be configured with a new IP address.	 For  example,	if
       you  have  a  personal computer that you use at home and in the office, do not use the same IP address for the network interface at home as
       you use in the office.  Use the netsetup utility for the initial SLIP configuration.  If you need to change the IP address, see the  Chang-
       ing the IP Address section in this reference page.

Managing Routing
       You can use either the routed or the gated daemon to manage routing, if you are not using the SLIP connection solely to communicate between
       the two systems making the connection.

       If you plan to use a system as an IP router, it must be configured to allow the forwarding of IP packets.  For more information on  setting
       a system up as an IP router, see the Network Administration manual and iprsetup(8).

       You  should  restart the routed or gated process if either was running prior configuring the SLIP interface with the ifconfig command. This
       ensures that the SLIP interface is recognized by the routed or gated daemon.

Using SLIP Physical Connections
       You can use SLIP to connect systems either directly (using a null modem) or over telephone lines using modems.

       If you connect the systems directly, use an RS-232 cable to connect the serial ports on the two hosts. The cable used must be a null  modem
       cable, such as Compaq BC22D-xx, (where xx varies depending on the length of the cable).

       You can use this method for hosts in close proximity to each other.  The maximum length of this type of connection is defined by the RS-232
       standard.

       If the systems are not in close proximity to each other, you can connect them using telephone line and modems. To use this kind of  connec-
       tion,  attach  a  modem to a serial port on both hosts so that the two hosts can establish a serial connection between them. You can use an
       RS-232 cable connected to the serial port on the host. This cable must be a straight-through cable such as Compaq BC22E-xx or BC22F-xx  and
       the modems must be set to 8 bit no parity.

Modems
       SLIP  works  best when hardware control flow is used.  High speed modems often fall-back to a lower data rate when line degradation occurs.
       To support hardware flow control you must use 25 pin connectors.

									  Note
       Do not use XON/XOFF flow control.  It will corrupt the data stream causing the TCP layer over IP to issue  retransmit  requests	for  over-
       runs.

       The  modems  you  use with SLIP should be able to handle a baud rate of 38,400.	If the modems you plan to use cannot handle a baud rate of
       38,400, you should set them to the highest baud rate to which they can be set.  For example, DEC V32 modems can handle  baud  rates  up	to
       19,200; however, they cannot be locked at this baud rate.  The highest baud rate they can be set to is 9,600.

       The  modems  should  also be V32bis compliant with V42bis compression.  Alternatively, the modems can support the Microcom Network Protocol
       (MNP), because both V42bis and MNP implement a subset of the other protocol.

       Use either the tip or kermit command to connect the modem.

									  Note
       Be sure you do not have a getty process running on the port to which the modem is connected.

       To  use	the  tip  command,  perform  the  following  steps:  Add  a  line  such  as  the  following  to  your	/etc/remote   file:   REM-
       SYS:dv=/dev/tty00:br#38400:pa=none  In  this  example:  Is  the name of the remote system to which you want to connect.	Specifies the tty.
       Note, if you are running UUCP, tty00 is renamed to ttyd0.  Specifies a baud rate of 38,400.  Specifies no parity.  Issue the  tip  command.
       For  example,  prompt>  tip  REMSYS If the tip command is successful, you get a connected message.  Suspend the process and return to local
       mode.

	      If you used the tip command to initiate the connection, issue the key sequence.  (If you use  Kermit,  issue  the  followed  by  key
	      sequence.  Enter the slattach command.  For example: prompt> slattach /dev/tty00 38400 Use the ping command to wake up the interface
	      on the remote system.  For example: prompt> ping REMSYS It may take a few ping messages to wake up the remote interface.

       Alternatively, you can leave slattach running on the remote system and rely on modem passwords and callback for security.

       For more information on the tip command, see the tip(1) reference page and the Command and Shell User's Guide.

Setting Up SLIP
       To configure your system to use SLIP, perform the following steps: Add the SLIP option to the host's kernel.

	      By default, an entry for SLIP exists in the system configuration file, /sys/conf/HOSTNAME (where HOSTNAME is the name of	your  sys-
	      tem).   The  SLIP  option is not included by default on 24 MB configurations systems.  On these systems, you must configure the SLIP
	      option into the kernel.

	      The entry appears as follows: options	SL This entry provides the host with one SLIP interface  (sl0).   You  can  override  this
	      option  by  specifying  the  nslip  parameter  in the /etc/sysconfigtab file.  For example, the following example specifies two SLIP
	      interfaces (sl0 and sl1): net:	  nslip=2

	      For more information, see the section on configuring the kernel in the System Administration manual.  Add entries to the	/etc/hosts
	      file for the network adapters at both ends of the SLIP network.

	      For  example: 129.34.0.1	   sys2_sl  sys2_sl.sl.abc.com 129.34.0.2     hst2_sl  hst2_sl.sl.abc.com Configure the SLIP interfaces by
	      using the ifconfig command.  For example: # ifconfig sl0 129.34.0.1 129.34.0.2 netmask 255.255.0.0 On hst2 ,  you  could	issue  the
	      following command: # ifconfig sl0 129.34.0.2 129.34.0.1 netmask 255.255.0.0 In these examples, the first argument is the name of the
	      SLIP pseudodevice, the second argument is the local address of the SLIP interface, the third argument is the  address  of  the  SLIP
	      interface on the remote host, and the remaining arguments specify the network mask.

	      For more information, see the ifconfig(8) reference page.  Attach a serial line to a SLIP interface by using the slattach command.

	      You  use	the  slattach  command to select the serial line that will be attached to the SLIP interface. The slattach command is also
	      used to enable or disable the SLIP options. For more information on specifying options, see the slattach(8) reference page.

	      When you use the slattach command, you do not specify the SLIP interface to be used (sl0, sl1,...).  Instead, the  first	configured
	      SLIP  interface (one for which you issued an ifconfig command) that is not already attached is used.  You also specify the baud rate
	      for the serial connection with the slattach command. If you do not specify a rate, it uses the default rate of 9600 baud.  The  fol-
	      lowing is an example of using the slattach command:

	      #  slattach  tty00  9600 In this example, tty00 attaches to a SLIP interface and sets the baud rate to 9600. The connection will use
	      the options that were previously set. (When you boot the system, no SLIP options are enabled.)

	      The following is another example of the slattach command:

	      # slattach +c -i tty00 In this example, tty00 attaches  to a SLIP interface running at 9600 baud (the default  speed).   TCP  header
	      compression is enabled and ICMP traffic suppression is disabled. (Disabling an option has no effect, if it was previously disabled.)

	      For more information on the slattach command, refer to the slattach(8) reference page.

       After  completing  these  steps, the SLIP network is available as long as the physical connection is ready and the slattach command is run-
       ning. The ps command can be used to ensure the slattach command is running.  If at any time the slattach command exits (due to a system	or
       network error), the command can be executed again to reestablish the SLIP network.

       The physical connection is always ready if a direct connection is being used.  For phone connections, the connection is readied by manually
       dialing the modem on the local system to connect to the modem on the remote system.  Once the remote modem answers,  the  data/talk  button
       (or equivalent) should be pressed to allow the modem on the local host to assume control of the connection.  Depending on the type of modem
       used, the connection might take a few seconds while the modems negotiate speeds, protocols, and other session parameters before it is ready
       for  use.  The  connection  should  stay  up  until one side hangs up due to some error or a user intentionally disconnects by pressing the
       data/talk button.

Stopping and Restarting SLIP
       You stop the SLIP network by using the kill command to stop the running slattach process that has attached a serial line to SLIP.  You  can
       restart	the SLIP network by reissuing the slattach command, which readies the physical connection. When disabling a SLIP network that runs
       over a phone connection, press the data/talk button on the modem to hang up the line.

Changing the IP Address
       To change the IP addresses used on a SLIP interface do the following: Issue the following command to stop the slattach connection:  #  kill
       slattach Issue the ifconfig command to deactivate the interface.  For example: # ifconfig sl0 down Issue the ifconfig command to delete the
       current local SLIP address.  For example: # ifconfig sl0 delete 15.141.63.153 Issue the ifconfig command to configure the  SLIP	interface.
       For  example:  #  ifconfig sl0 15.142.63.153 15.143.65.163 In this example, 15.142.63.153 is the local SLIP IP address and 17.143.65.163 is
       SLIP IP address on the remote system to which you will connect.	Issue the slattach command to attach the serial line to the network inter-
       face.

RELATED INFORMATION

       Commands:  ifconfig(8), netstat(1)

       Network Administration delim off

															      slip_manual_setup(7)