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: src/sbin/nos-tun/nos-tun.8,v 1.6.2.6 2003/02/23 20:53:46 trhodes Exp $ 10.\" $DragonFly: src/sbin/nos-tun/nos-tun.8,v 1.3 2004/03/11 12:28:54 hmp Exp $ 11.\" 12.Dd April 11, 1998 13.Dt NOS-TUN 8 14.Os 15.Sh NAME 16.Nm nos-tun 17.Nd implement ``nos'' or ``ka9q'' style IP over IP tunnel 18.Sh SYNOPSIS 19.Nm 20.Fl t 21.Ar tunnel 22.Fl s 23.Ar source 24.Fl d 25.Ar destination 26.Fl p 27.Ar protocol_number 28.Ar target 29.Sh DESCRIPTION 30The 31.Nm 32utility is used to establish an 33.Em nos 34style tunnel, (also known as 35.Em ka9q 36or 37.Em IP-IP 38tunnel) using a 39.Xr tun 4 40kernel interface. 41.Pp 42.Ar Tunnel 43is the name of the tunnel device 44.Pa /dev/tun0 45for example. 46.Pp 47.Ar Source 48and 49.Ar destination 50are the addresses used on the tunnel device. 51If you configure the tunnel against a cisco router, use a netmask of 52.Dq 255.255.255.252 53on the cisco. This is because the tunnel is a point-to-point interface 54in the 55.Dx 56end, a concept cisco doesn't really implement. 57.Pp 58.Ar Protocol number 59sets tunnel mode. 60Original KA9Q NOS uses 94 but many people use 4 61in worldwide backbone of ampr.org. 62.Pp 63.Ar Target 64is the address of the remote tunnel device, this must match the source 65address set on the remote end. 66.Sh EXAMPLES 67This end, a 68.Dx 69box on address 192.168.59.34: 70.Bd -literal -offset indent 71nos-tun -t /dev/tun0 -s 192.168.61.1 -d 192.168.61.2 192.168.56.45 72.Ed 73.Pp 74Remote cisco on address 192.168.56.45: 75.Bd -literal -offset indent 76interface tunnel 0 77ip address 192.168.61.2 255.255.255.252 78tunnel mode nos 79tunnel destination 192.168.59.34 80tunnel source 192.168.56.45 81.Ed 82.Sh BUGS 83We don't allow for setting our source address for multihomed machines. 84.Sh AUTHORS 85.An -nosplit 86.An Nickolay N. Dudorov Aq nnd@itfs.nsk.su 87wrote the program, 88.An Poul-Henning Kamp Aq phk@FreeBSD.org 89wrote the man-page. 90.An Isao SEKI Aq iseki@gongon.com 91added a new flag, IP protocol number. 92