slip(1M) slip(1M)NAME slip - attach a dialup serial line as a network interface SYNOPSIS /etc/slip DESCRIPTION slip is used to assign a dial-up tty line to a network in- terface and to define the network source and destination ad- dresses of the point-to-point link. The assignment and de- finition are made on the basis of the user requesting slip, the slip user names-to-host configuration file /etc/slip.hosts, and the slip configuration files /etc/slip.config and /etc/slip.user. A user first connects to a slip server via a dial-up or hard-wired connection, such as by using cu, kermit, or tip. After a user establishes a connection, the user invokes slip on the server to attach the serial line as a network inter- face. When a user invokes slip using a dialup or hard-wired termi- nal, the user's ID and the available slip interfaces are checked against /etc/slip.user. If the user ID is valid and there are available unused slip interfaces, the file /etc/slip.user is updated to reflect the use of a slip in- terface by that user. After invoking slip, the user no longer has access to the dial-up terminal line for issuing commands to the shell. The user must return to the local machine and invoke either slattach or slattconf to bring up the local end of the slip link. After running slattconf, the user can invoke telnet, rlogin, or other network programs from the local machine. The kernels of both the local machine and the remote machine must be configured to support the slip interface. For A/UX machines, to configure your kernel for slip, use /etc/newconfig nfs slip or /etc/newconfig bnet slip After executing the two lines above, you need to modify /etc/inittab to turn on the networking daemons. Then reboot to run the new networking kernel. FILES The /etc/hosts file must be appropriately configured on the client machine before slip is invoked. The April, 1990 1
slip(1M) slip(1M)/etc/slip.config, /etc/slip.hosts, /etc/slip.user, and /etc/hosts files must be appropriately configured on the slip server before slip is invoked. If your machine is a slip client machine, the only file you have to modify is /etc/hosts. The /etc/hosts file on the client must contain the usable Internet address when the client invokes slip. The slip- server Internet address must also be included in this file. Ask the system administrator of the slip server for the In- ternet addresses to include in this file. A sample /etc/hosts file is: 0x7F.0x00.0x00.0x01 loop lo loo 128.120.254.3 hostname1 #slip server 128.120.253.1 hostname2 #slip client The first line contains the loopback address; this line is always present in the /etc/hosts file. The second line in the example is the Internet address and host address of the slip-server. The third line is the client Internet address and hostname used when the client makes a slip connection. The system administrator of the slip host must modify the /etc/slip.config, /etc/slip.hosts, and /etc/slip.user files. A sample slip.config configuration file is # slip.config configuration file # Each line configures a serial line # 128.120.254.3 128.120.254.3 Each line is a slip-server host address for each of the slip interfaces supported by the slip-server host. In the previ- ous example, the host has two slip interfaces available for user dialup use. An example of a slip.hosts file is # dialup slip.hosts table # maps usercodes to host addresses # 128.120.253.1 joe 128.120.253.2 chris 128.120.253.3 mike 128.120.253.4 linda The Internet address in the first field is used when the user specified in the second field invokes slip. 2 April, 1990
slip(1M) slip(1M)The slip user file /etc/slip.user is not human readable. You create the /etc/slip.user file by creating the /etc/slip.config file and then running mkslipuser. Use the command dslipuser to display the contents of the user file, and to report the number of slip users on the system and the number of available slip interfaces. DIAGNOSTICS When a slip command succeeds, one of two messages is print- ed. Attaching source-host-name (aa.bb.cc.dd) to domain domain-name via slip-server-host-name (ee.ff.gg.hh) or Attaching source-host-name (aa.bb.cc.dd) to network via slip-server-host-name (ee.ff.gg.hh) When a slattconf command succeeds, the following message is displayed, sln The n is replaced by the slip interface used by the new slip connection. Any of the following error messages indicate that the slip command failed. Note that the error-string reports in the following messages are generated by perror. /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 In addition, the diagnostic Connection failure: may be ac- companied by any of the following messages. Bad login name Can't open list of valid user-host mappings User userid 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 hostname is already attached All lines are busy. Try again later. The following error message is a warning that setting the April, 1990 3
slip(1M) slip(1M)subnet mask for the slip point-to-point line failed. The line is brought up using a standard internet address. ioctl SIOCSIFNETMASK: error-string SEE ALSO netstat(1), dslipuser(1M), ifconfig(1M), mkslipuser(1M), hosts(4), slip.config(4), slip.hosts(4), slip.user(4). BUGS slip has a fixed definition slip-netmask that may be defined in /etc/hosts. This slip-netmask allows you one and only one subnet mask for all slip hosts. This should be confi- gurable per slip host. If the slip netmask is defined on the slip server then you must specify a matching netmask in the netmask option of the slattconf command. slip lines require careful handling by the router or by spe- cial hand-installed routes on the slip-server-host. The In- ternet router shipped with A/UX (in.routed) handles slip correctly. Most Internet routers do not. 4 April, 1990