1.\" 2.\" ---------------------------------------------------------------------------- 3.\" "THE BEER-WARE LICENSE" (Revision 42): 4.\" <phk@FreeBSD.org> wrote this file. As long as you retain this notice you 5.\" can do whatever you want with this stuff. If we meet some day, and you think 6.\" this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 7.\" ---------------------------------------------------------------------------- 8.\" 9.\" $FreeBSD$ 10.\" 11.Dd April 11, 1998 12.Dt NOS-TUN 8 13.Os 14.Sh NAME 15.Nm nos-tun 16.Nd implement ``nos'' or ``ka9q'' style IP over IP tunnel 17.Sh SYNOPSIS 18.Nm 19.Fl t 20.Ar tunnel 21.Fl s 22.Ar source 23.Fl d 24.Ar destination 25.Fl p 26.Ar protocol_number 27.Ar target 28.Sh DESCRIPTION 29.Nm Nos-tun 30is used to establish an 31.Em nos 32style tunnel, (also known as 33.Em ka9q 34or 35.Em IP-IP 36tunnel) using a 37.Xr tun 4 38kernel interface. 39.Pp 40.Ar Tunnel 41is the name of the tunnel device 42.Pa /dev/tun0 43for example. 44.Pp 45.Ar Source 46and 47.Ar destination 48are the addresses used on the tunnel device. 49If you configure the tunnel against a cisco router, use a netmask of 50.Dq 255.255.255.252 51on the cisco. This is because the tunnel is a point-to-point interface 52in the 53.Fx 54end, a concept cisco doesn't really implement. 55.Pp 56.Ar Protocol number 57sets tunnel mode. 58Original KA9Q NOS uses 94 but many peoples use 4 59in worldwide backbone of ampr.org. 60.Pp 61.Ar Target 62is the address of the remote tunnel device, this must match the source 63address set on the remote end. 64.Sh EXAMPLES 65This end, a 66.Fx 67box on address 192.168.59.34: 68.Bd -literal -offset indent 69nos-tun -t /dev/tun0 -s 192.168.61.1 -d 192.168.61.2 192.168.56.45 70.Ed 71.Pp 72Remote cisco on address 192.168.56.45: 73.Bd -literal -offset indent 74interface tunnel 0 75ip address 192.168.61.2 255.255.255.252 76tunnel mode nos 77tunnel destination 192.168.59.34 78tunnel source 192.168.56.45 79.Ed 80.Sh BUGS 81We don't allow for setting our source address for multihomed machines. 82.Sh AUTHORS 83.An -nosplit 84.An Nickolay N. Dudorov Aq nnd@itfs.nsk.su 85wrote the program, 86.An Poul-Henning Kamp Aq phk@FreeBSD.org 87wrote the man-page. 88.An Isao SEKI Aq iseki@gongon.com 89added a new flag, IP protocol number. 90