3 6in4 - configure and run automatic or manual 6to4 tunnel of IPv6 through IPv4
20 sets up and maintains a tunnel of IPv6 traffic through an IPv4 connection.
25 define the IPv6 address and subnet of the near end of the tunnel
37 .BI 2002: aabb : ccdd ::1/48
45 are the hexadecimal equivalents of the bytes
48 in this host's primary IPv4 address.
51 is the IPv4 address of the far end of the tunnel
52 (must be given explicitly for a configured tunnel, or
53 defaults to the anycast address 192.88.99.1 for
57 is the IPv6 address of the far end of the tunnel
58 (used as the point-to-point destination for routing, and
59 defaults to a link-local address constructed from
63 forks a pair of background processes to copy packets to and from
71 permit any remote IPv4 address as the far end of a tunnel.
72 This is likely to be useful for the server side of a tunnel.
75 use the tunnel as the default route for global IPv6 addresses
78 use the network mounted at
84 If your primary IPv4 address is public,
93 Similarly, you can start a server for
101 If you use a tunnel broker at address
103 configured to give you a
106 .LR 2001:1122:3344:5566:: ,
107 you can start the tunnel with
110 ip/6in4 -g 2001:1122:3344:5566::/64 5.6.7.8
117 access to IPv6-in-IPv4 packets
120 packet interface to IPv6 network
134 Needs a kernel with an
138 The tunnel client filters addresses fairly conservatively in both directions.
139 However it's not watertight,
140 and may be flakey in other ways so don't put too much trust in it.