SL(4)

NAME
sl - Serial Line IP (SLIP) network interface

SYNOPSIS
pseudo-device sl [count]

DESCRIPTION
The sl interface allows asynchronous serial lines to be used as IP network interfaces using the SLIP protocol. The sl interface can use Van Jacobson TCP header compression and ICMP filtering.

However, SLIP can only transmit IP 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 This is why SLIP has been superceded by the Point-to-Point Protocol (PPP), which does all of those things, and much more.

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
intro(4), inet(4), ppp(4), slattach(8), sliplogin(8), slstats(8) RFC, 1055, June 1988, A Nonstandard for Transmission of IP Datagrams over Serial Lines: SLIP.

HISTORY
The sl device appeared in NetBSD 1.0.