nos-tun(8)

NAME

nos-tun - implement ``nos'' or ``ka9q'' style IP over IP

tunnel

SYNOPSIS

nos-tun    -t   tunnel   -s   source   -d   destination   -p
protocol_number [source]
        target

DESCRIPTION

The nos-tun utility is used to establish an nos style tun

nel, (also known
as ka9q or IP-IP tunnel) using a tun(4) kernel interface.

Tunnel is the name of the tunnel device /dev/tun0 for exam

ple.

Source and destination are the addresses used on the tunnel

device. If
you configure the tunnel against a cisco router, use a net

mask of
``255.255.255.252'' on the cisco. This is because the tun

nel is a pointto-point interface in the FreeBSD end, a concept cisco does

not really
implement.

Protocol number sets tunnel mode. Original KA9Q NOS uses 94

but many
people use 4 on the worldwide backbone of ampr.org.

Target is the address of the remote tunnel device, this must

match the
source address set on the remote end.

EXAMPLES

This end, a FreeBSD box on address 192.168.59.34:

nos-tun -t /dev/tun0 -s 192.168.61.1 -d 192.168.61.2

192.168.56.45

Remote cisco on address 192.168.56.45:

interface tunnel 0
ip address 192.168.61.2 255.255.255.252
tunnel mode nos
tunnel destination 192.168.59.34
tunnel source 192.168.56.45

AUTHORS

Nickolay N. Dudorov <nnd@itfs.nsk.su> wrote the program,

Poul-Henning
Kamp <phk@FreeBSD.org> wrote the man-page. Isao SEKI <ise

ki@gongon.com>
added a new flag, IP protocol number.

BUGS

We do not allow for setting our source address for multi

homed machines.

BSD April 11, 1998

BSD