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sl(4) [netbsd man page]

SL(4)							   BSD Kernel Interfaces Manual 						     SL(4)

NAME
sl -- Serial Line IP (SLIP) network interface SYNOPSIS
pseudo-device sl DESCRIPTION
The sl interface allows asynchronous serial lines to be used as IPv4 network interfaces using the SLIP protocol. To use the sl interface, the administrator must first create the interface and assign a tty line to it. The sl interface is created using the ifconfig(8) create subcommand, and slattach(8) is used to assign a tty line to the interface. Once the interface is attached, network source and destination addresses and other parameters are configured via ifconfig(8). The sl interface can use Van Jacobson TCP header compression and ICMP filtering. The following flags to ifconfig(8) control these properties of a SLIP link: link0 Turn on Van Jacobson header compression. -link0 Turn off header compression. (default) link1 Don't pass through ICMP packets. -link1 Do pass through ICMP packets. (default) link2 If a packet with a compressed header is received, automatically enable compression of outgoing packets. (default) -link2 Don't auto-enable compression. DIAGNOSTICS
sl%d: af%d not supported . The interface was handed a message with addresses formatted in an unsuitable address family; the packet was dropped. SEE ALSO
inet(4), intro(4), ppp(4), strip(4), ifconfig(8), slattach(8), sliplogin(8), slstats(8) J. Romkey, A Nonstandard for Transmission of IP Datagrams over Serial Lines: SLIP, RFC, 1055, June 1988. Van Jacobson, Compressing TCP/IP Headers for Low-Speed Serial Links, RFC, 1144, February 1990. HISTORY
The sl device appeared in NetBSD 1.0. BUGS
SLIP can only transmit IPv4 packets between preconfigured hosts on an asynchronous serial link. It has no provision for address negotiation, carriage of additional protocols (e.g. XNS, AppleTalk, DECNET), and is not designed for synchronous serial links. This is why SLIP has been superseded by the Point-to-Point Protocol (PPP), which does all of those things, and much more. BSD
July 9, 2006 BSD

Check Out this Related Man Page

slattach(8)						      System Manager's Manual						       slattach(8)

NAME
slattach - Attaches a serial line to a network interface SYNOPSIS
/usr/sbin/slattach [{+|-} {c|e|i}] ttyname [baudrate] DESCRIPTION
The slattach command assigns a tty line to a network interface, allowing terminal devices to communicate across a network. The ttyname argument is the name of any valid tty device in /dev. This can be either the full path name (for example, /dev/tty01) or the name in /dev (for example, tty01). The optional baudrate argument is used to set the speed of the connection. The default speed is 9600 baud. The tty line is attached to the first available network interface (sl0, sl1, already be configured with the local and remote addresses of each end of the SLIP connection (see ifconfig(8)). Only a person with superuser authority can attach a network interface. To detach the interface, use the ifconfig interface_id down command after terminating the slattach process. interface_id is the name that is shown by the netstat command. FLAGS
Enables (+) or disables (- TCP header compression. Enables (+) or disables (- automatic TCP header compression. If enabled and the remote system is using TCP header compression, TCP header compression is automatically enabled on the local system. If both local and remote sys- tems have enabled this flag, TCP header compression is not used. One system must force the use of TCP header compression. Enables (+) or disables (- ICMP traffic suppression. If enabled, ICMP traffic (like that generated by ping(8)) is not allowed to pass over the SLIP con- nection. When the system is booted, all flags are initially disabled. Once a flag is enabled, it remains enabled until the system is rebooted or until another slattach command is issued with the flag disabled. NOTES
The slattach command requires the Serial Line Internet Protocol (SLIP), which the kernel must support. If making a SLIP connection to another Tru64 UNIX system, both systems must run slattach. If making a SLIP connection to a system not running the Tru64 UNIX operating system, the other system must support the SLIP protocol. EXAMPLES
To attach a tty device to a network interface, enter: /usr/sbin/slattach /dev/tty01 4800 This command attaches tty01 to a network interface to be used by the Serial Line Internet Protocol (SLIP). The connection speed is 4800 baud. To attach a tty device to a network interface at 19200 bits per second (bps), with TCP header compression enabled and ICMP traffic suppres- sion disabled, enter: /usr/sbin/slattach +c -i /dev/tty01 19200 FILES
Specifies the command path Contains the slattach process ID RELATED INFORMATION
Commands: netstat(1), ifconfig(8) Specifications: SLIP is described in RFC1055. TCP header compression is described in RFC1144. delim off slattach(8)
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