Attach serial lines as network interfaces


slattach [-Hhlmn] [-s baudrate] [-t ldisc] ttyname

Runs on:

QNX Neutrino


Turn on DTR/CTS flow control. By default, no flow control is done.
Turn on RTS/CTS flow control. By default, no flow control is done.
Turn on the CLOCAL flag, making it possible to run SLIP on a cable without modem control signals (e.g., DTR, DSR, DCD).
Maintain modem control signals after closing the line. Specifically, this disables HUPCL.
Don't detach from invoking tty.
-s baudrate
The speed of the connection. If not specified, the default of 9600 is used.
-t ldisc
Specifies the line discipline to use for the tty. The only currently support line discipline is slip (the default), which creates an SL instance.
The name of the TTY device, a string in the form ttyXX or /dev/ttyXX.


You can use slattach to assign a TTY line to a network interface that uses asynchronous serial lines.

Currently you use slattach to attach an SL instance (see You have to create an interface, using the ifconfig create subcommand, before using slattach. You can then configure the network source and destination addresses and other interface parameters via ifconfig.

Note: Only the superuser may attach a network interface.

To detach the interface, use ifconfig interface-name down after killing off the slattach process. The interface-name is the name that's shown by netstat.

There's no way to specify the interface name (sl%d, etc.) to be attached by the slattach command. There's also no way to see which interface is assigned to the specified TTY by the slattach command.


Messages indicating that the specified interface is not configured or created, the requested address is unknown, or that the user is not privileged but tried to alter an interface's configuration.


mount -Tio-pkt
ifconfig sl0 create
slattach -t slip -s 115200 /dev/serusb1
ifconfig sl0 inet

slattach ttyh8

slattach -s 4800 /dev/tty01

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