SLIP Configuration

This section explains how to configure Serial Line Internet Protocol (SLIP) with the ChorusOS 4.0 product standard interface and drivers. It assumes the serial line or modem is already physically connected.

Systems often have two IP addresses: one for Ethernet, one for SLIP.

This document differentiates between Ethernet Internet addresses and SLIP addresses. As you read, be aware that hostname refers to the Ethernet hostname corresponding to the Ethernet IP address, and that hostname_SLIP refers to the hostname corresponding to the SLIP address.

Before starting SLIP, make sure that the target system SLIP interface is correctly registered on the local network with the correct IP address, in particular for NFS access.

This section also assumes that you have configured your ChorusOS system image to support the SLIP connection and created the SLIP interface at boot time, even if your system image does not include everything necessary to establish a SLIP connection at boot time.

SLIP as implemented in ChorusOS 4.0 handles attaching the SLIP interface to the serial line using the slattach command, and the chat command to handle modem connections and authentication.

Enabling SLIP at Boot Time by Including slattach in the System Image

1. Change to the directory where you build system images:

   host% cd build_dir

2. Ensure that both serial lines and network interfaces are available for SLIP by including the necessary commands in the conf/sysadm.ini that you build into the system image. For example:

   mkdev tty 0 /pci/pci-isa/ns16550-2      # Create a tty interface
                                           # using the second serial port
                                           # because the first is reserved
                                           # for the tip line.
   
   mkdev sl 0                              # Create a SLIP interface that is
                                           # not bound to the tty yet.
   
   mknod /dev/tty01 c 6 0                  # Create a tty special file
   
   # Simple initialization of direct serial line connection
   # Requires slattach in system image
   #
   arun /image/sys_bank/slattach -s 38400 -l /dev/tty01 &
   
   # Initialization using chat to connect through a modem
   # Requires slattach.r, chat.r and chat.cmd in system image
   #
   #arun /image/sys_bank/slattach -z -r "'/image/sys_bank/chat \
   #-f /image/sys_bank/chat.cmd'" /dev/tty01 &
   
   # Configure the SLIP interface
   # Syntax: ifconfig *interface* *target_SLIP* *host_SLIP* netmask *NETMASK*
   #
   ifconfig sl0 129.157.197.88 129.157.197.144 netmask 255.255.255.0

   See the appropriate document in the ChorusOS 4.0 Target Family Documentation Collection for serial device IDs for other serial line hardware.

3. Start the ews configuration utility:

   host% ews conf/ChorusOS.xml &

4. Use the hints in the table below to set system image features and tunables:

   Set...	Comments
   VTTY=true	SLIP requires virtual ttys.
   SLIP=true
   iom.nfs.rsize=512	Optimizing NFS read and write buffer sizes for use with SLIP by setting them to a maximum of 512 (must be less than the Maximum Transfer Unit size).
   iom.nfs.wsize=512

5. Include the slattach.r actor in the system image.

6. (Optional) If you need chat, include the chat.r actor in the system image.

7. (Optional) If you need chat and it needs a chat script, modify the conf/chat.cmd file, and include it in the system image. An example chat script follows:

   # Abort if we cannot contact the remote system
   ABORT            BUSY
   ABORT            'NO CARRIER'
   # Wait seven seconds max. for the remote system to reply
   TIMEOUT          7
   # Reset the modem, enable RTS/CTS
   ''               ATZ
   OK               AT&K3
   # Dial the number 1234567890
   OK               ATDT1234567890
   # Wait one minute max. for the connection
   TIMEOUT          60
   CONNECT
   ECHO             OFF
   # Wait for the reply
   TIMEOUT          7
   # Login as chatuser with pa55worD
   ogin:-\\r-ogin:  chatuser
   ssword:          pa55worD
   SAY              "Logged in successfully."

8. Rebuild the system image.

9. Copy the system image to the boot server:

   host% rcp system_image_name boot_server:/tftpboot

10. Reboot the target system:

    host% rsh target reboot

Starting SLIP from the Command Line

Start SLIP by running slattach as an actor:

host% rsh target_SLIP arun /bin/slattach [options]