NOS-TUN(8)						    BSD System Manager's Manual 						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 tunnel, (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 example.

     Source and destination are the addresses used on the tunnel device.  If you configure the tunnel against a cisco router, use a netmask of
     ``255.255.255.252'' on the cisco.	This is because the tunnel is a point-to-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
     <iseki@gongon.com> added a new flag, IP protocol number.

BUGS

     We do not allow for setting our source address for multihomed machines.

BSD
								  April 11, 1998							       BSD