xref: /freebsd/sbin/nos-tun/nos-tun.8 (revision e0c4386e) 
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.Dd October 5, 2016
10.Dt NOS-TUN 8
11.Os
12.Sh NAME
13.Nm nos-tun
14.Nd implement ``nos'' or ``ka9q'' style IP over IP tunnel
15.Sh SYNOPSIS
16.Nm
17.Fl t
18.Ar tunnel
19.Fl s
20.Ar source
21.Fl d
22.Ar destination
23.Fl p
24.Ar protocol_number
25.Op Ar source
26.Ar target
27.Sh DESCRIPTION
28The
29.Nm
30utility is 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.
52This is because the tunnel is a point-to-point interface
53in the
54.Fx
55end, a concept cisco does not really implement.
56.Pp
57.Ar Protocol number
58sets tunnel mode.
59Original KA9Q NOS uses 94 but many people use 4
60on the worldwide backbone of ampr.org.
61.Pp
62.Ar Target
63is the address of the remote tunnel device, this must match the source
64address set on the remote end.
65.Sh EXAMPLES
66This end, a
67.Fx
68box on address 192.168.59.34:
69.Bd -literal -offset indent
70nos-tun -t /dev/tun0 -s 192.168.61.1 -d 192.168.61.2 192.168.56.45
71.Ed
72.Pp
73Remote cisco on address 192.168.56.45:
74.Bd -literal -offset indent
75interface tunnel 0
76ip address 192.168.61.2 255.255.255.252
77tunnel mode nos
78tunnel destination 192.168.59.34
79tunnel source 192.168.56.45
80.Ed
81.Sh HISTORY
82The
83.Nm
84utility appeared in
85.Fx 3.0 .
86.Sh AUTHORS
87.An -nosplit
88.An Nickolay N. Dudorov Aq Mt nnd@itfs.nsk.su
89wrote the program,
90.An Poul-Henning Kamp Aq Mt phk@FreeBSD.org
91wrote the man-page.
92.An Isao SEKI Aq Mt iseki@gongon.com
93added a new flag, IP protocol number.
94.Sh BUGS
95We do not allow for setting our source address for multihomed machines.
96