slip(1M) slip(1M)NAME slip - assigns a serial line to a network interface SYNOPSIS slip DESCRIPTION slip assigns a serial line to the Compressed Serial Line/Internet Protocol (CSL/IP) network interface. The serial line can be a dial-up or a hard-wired connection between the client system and the CSL/IP server. The slip command defines the network source and destination addresses of the point-to-point link on the basis of your login name and information in the /etc/slip.hosts and /etc/slip.config files. To run slip, you need to configure a kernel that supports networking and CSL/IP, and you need to configure the client system and the CSL/IP server. You can do these tasks in any order. Configuring the Kernel The kernels of both the client system and the CSL/IP server must be configured to support networking and the CSL/IP interface. For A/UX systems, use one of these commands to configure your kernel for CSL/IP: newconfig bnet cslip newconfig nfs cslip Specifying bnet causes newconfig to include Berkeley Networking Services (TCP/IP) in the new kernel, which then supports rlogin, rcp, telnet, and other networking commands. Specifying nfs causes newconfig to include Network File System (NFS) in the new kernel, which supports remote mounting of file systems as well as TCP/IP. If you specify bnet, you will not be able to use CSL/IP to mount remote file systems. To run the new networking kernel that is created by newconfig, reboot the system. Configuring the Client System for CSL/IP The system administrator of the client system must modify the file /etc/hosts. This file must contain the Internet address of the server and the client. Here is an example of /etc/hosts: 0x7F.0x00.0x00.0x01 loop lo loo 128.120.253.1 mitakola #cslip client 128.120.254.3 twosocks #cslip server The first line is the loopback address. The second line is the Internet address and host name of the host system, which January 1992 1
slip(1M) slip(1M)in this case is a client system. The first and second lines are always present in /etc/hosts. The third line is the Internet address and host name of the CSL/IP server. Configuring the CSL/IP Server The system administrator of the CSL/IP server must modify the /etc/hosts, /etc/slip.hosts, and /etc/slip.config files. The /etc/hosts file contains an entry for each client system that has users who intend to establish a CSL/IP connection from the client system to the CSL/IP server. The entries consist of the Internet address and host name of the client system. Here is an example of /etc/hosts: 0x7F.0x00.0x00.0x01 loop lo loo 128.120.254.3 twosocks #cslip server 128.120.253.1 mitakola #cslip client 128.120.253.2 halifax #cslip client 128.120.253.3 phant #cslip client 128.120.253.4 xerxes #cslip client The first line is the loopback address. The second line is the Internet address and host name of the host system, which in this case is the CSL/IP server. The first and second lines are always present in /etc/hosts. The remaining lines are client systems. The /etc/slip.hosts file consists of entries that associate the Internet address of client systems with the login name of a user on the CSL/IP server. Here is an example of a /etc/slip.hosts file: 128.120.253.1 joe 128.120.253.2 chris 128.120.253.3 mike 128.120.253.4 linda If the user joe logs in to the CSL/IP server from a client system and runs slip, the Internet address of the client system must be 128.120.253.1 for slip to assign the serial line that joe is using. The /etc/slip.config file contains one or more entries, each of which consists of the Internet address of the CSL/IP server. You specify one entry for each serial line that you wish to configure as a CSL/IP line. For example, this /etc/slip.config file makes available as CSL/IP interfaces any two serial lines on the CSL/IP server: 128.120.254.3 128.120.254.3 2 January 1992
slip(1M) slip(1M)After you modify /etc/slip.config, run the mkslipuser command. The mkslipuser command uses /etc/slip.config to generate the binary file, /etc/slip.user, which is the actual file that slip examines to determine the number of available CSL/IP lines. See mkslipuser(1M) for details. Using slip To use slip, connect the client system to the CSL/IP server by means of a dial-up or a hard-wired connection; for instance, by running cu, kermit, or tip on the client system. When you establish the connection and log in to the CSL/IP server, run slip on the CSL/IP server to attach the serial line to the network interface. The slip command first checks /etc/slip.user for an available unused CSL/IP interface and then checks /etc/slip.hosts to verify your login name and the Internet address of your client system. If your login name and Internet address match an entry in /etc/slip.hosts and there is an available unused CSL/IP interface, slip updates /etc/slip.user to assign a CSL/IP interface to your line. Once this assignment is made, you can no longer issue commands to the shell. You must return to the client system and run slattach and ifconfig or slattconf, which runs ifconfig for you, to bring up the local end of the CSL/IP link. When the local end of the CSL/IP link is up, you can run telnet, rlogin, or other network programs from the client machine to the CSL/IP server. STATUS MESSAGES AND VALUES When successful, the slip command prints one of these messages: Attaching client-host-name (aa.bb.cc.dd) to domain domain-name via CSLIP-server-host-name (ee.ff.gg.hh) Attaching client-host-name (aa.bb.cc.dd) to network via CSLIP-server-host-name (ee.ff.gg.hh) Any of these error messages indicates that the slip command failed: /etc/slip.user: can't seek /etc/slip.user: can't write ioctl TCGETA: error-string ioctl TCSETA: error-string ioctl LDGETU: error-string ioctl SIOCSIFDSTADDR: error-string ioctl SIOCSIFADDR: error-string ioctl SIOCSIFNETMASK: error-string Connectionfailure: January 1992 3
slip(1M) slip(1M)See intro(2) for an explanation of error-string. The message ioctl SIOCSIFNETMASK: error-string is a warning that setting the subnet mask for the slip point-to-point line failed. Try bringing the line up by using a standard Internet address instead. The message Connection failure: may be accompanied by any of the following messages: Bad login name Can't open list of valid user-host mappings User login-name is not authorized to connect to SLIP Invalid address aa.bb.cc.dd in hosts file Can't open SLIP user file Unable to lock SLIP user file Host host-name is already attached All lines are busy. Try again later. LIMITATIONS You can define a fixed-definition CSL/IP netmask in /etc/hosts. This netmask allows you one and only one subnet mask for all CSL/IP hosts. The netmask should be configurable on a per-host basis. If the CSL/IP netmask is defined on the CSL/IP server, you must specify the same netmask in the netmask argument to the ifconfig command. CSL/IP lines require careful handling by the router or by special hand-installed routes on the CSL/IP server. The Internet router shipped with A/UX (in.routed) handles slip correctly. Most Internet routers do not. FILES /etc/slip Executable file /etc/slip.config File that mkslipuser uses to generate /etc/slip.users /etc/slip.hosts File that slip checks to verify your login name and the Internet address of your client machine /etc/slip.users File that slip checks for an available CSL/IP interface SEE ALSO dslipuser(1M), ifconfig(1M), mkslipuser(1M), slattach(1M), slattconf(1M) netstat(1N) in A/UX Command Reference hosts(4), slip.config(4), slip.hosts(4), slip.user(4) in A/UX Programmer's Reference 4 January 1992