ip6conf.tproj/ip6config.8

   1 .\"     $NetBSD: 6to4.8,v 1.5 2001/12/03 19:03:21 wiz Exp $
   2 .Dd May 21, 2002
   3 .Dt ip6config 8
   4 .Os
   5 .Sh NAME
   6 .Nm ip6config
   7 .Nd Configure IPv6 and 6to4 IPv6 tunnelling
   8 .Sh SYNOPSIS
   9 .Nm
  10 .Op Fl h
  11 .Ar command interface
  12 .Sh DESCRIPTION
  13 The
  14 .Nm
  15 script can be used to start up or shut down IPv6 on active interfaces. It
  16 can also be used to configure a 6to4 tunnel and start or stop router
  17 advertisement.
  18 .Pp
  19 When IPv6 is enabled on an interface the protocol is attached to the
  20 interface, at which point the default settings in the kernel allow it
  21 to acquire a link-local address and listen for router advertisements.
  22 .Pp
  23 6to4 is a mechanism by which your IPv6 address(es) are derived from an
  24 assigned IPv4 address, and which involves automatic tunnelling to one or
  25 more remove 6to4 hubs, which will then forward your v6 packets on the
  26 6bone etc. Replies are routed back to you over IPv4 via (possibly) other
  27 6to4 capable remote gateways. As such, IPv6-in-IPv4-encapsulated
  28 packets are accepted from all v4-hosts.
  29 .Pp
  30 From your (single) IPv4 address, you get a whole IPv6 /48 network,
  31 which allows you to split your network in 2^16 subnets, with 2^64
  32 hosts each. You need to setup routing for your internal network
  33 properly, help is provided for setting up the border router here.
  34 .Pp
  35 This script takes the burden to calculate your IPv6 address from
  36 existing IPv4 address and runs the commands to setup (and tear down)
  37 automatic 6to4 IPv6 tunnelling.
  38 .Pp
  39 Finally, router advertisement for an internal network can be started
  40 and stopped. This uses sysctl to set net.inet6.ip6.forwarding and
  41 net.inet6.ip6.accept_rtadv to the proper values for routing.
  42 .Pp
  43 Possible options are:
  44 .Bl -tag -width xxx
  45 .It Fl h
  46 Show usage.
  47 .El
  48 .Pp
  49 Possible commands are:
  50 .Bl -tag -width start-rtadvd
  51 .It Sy start-v6
  52 Start IPv6 on given interface using default kernel settings. Attaches
  53 protocol to the interface. If interface is "all", all valid interfaces
  54 will be configured.
  55 .It Sy stop-v6
  56 Stop IPv6 on given interface. Detaches protocol from the interface. If
  57 interface is "all", all valid interfaces will be configured.
  58 .It Sy start-stf
  59 Configure 6to4 IPv6. The
  60 .Xr stf 4
  61 interface is configured, and a default route to a remote 6to4
  62 gateway is established. In addition, the internal
  63 network interface is assigned an address.
  64 .It Sy stop-stf
  65 Stops 6to4 IPv6. All addresses are removed from the
  66 .Xr stf 4
  67 device, and the default route is removed.
  68 .It Sy start-rtadvd
  69 Starts router advertizement and IPv6 packet forwarding,
  70 turning the machine into a IPv6 router.
  71 .Xr rtadvd 8
  72 is invoked with a custom config file created under
  73 .Pa /var/run .
  74 Clients just need to be told to accept router advertizements, i.e.
  75 the
  76 .Sq net.inet6.ip6.accept_rtadv
  77 sysctl needs to be set to
  78 .Sq 1 .
  79 You can arrange that by setting
  80 .Dq ip6mode=autohost
  81 in
  82 .Pa /etc/rc.conf .
  83 .It Sy stop-rtadvd
  84 Stops router advertizement and IPv6 packet forwarding.
  85 .Xr rtadvd 8
  86 is stopped, and the
  87 .Xr rtadvd.conf 5
  88 config file is removed from
  89 .Pa /var/run .
  90 .El
  91 .Sh REQUIREMENTS
  92 Besides IPv4 connectivity, you need support for IPv6 and the
  93 .Xr stf 4
  94 device in your kernel. This is provided beginning with Darwin
  95 Kernel Version 6.0.
  96 .Pp
  97 No special values are needed in
  98 .Pa /etc/rc.conf
  99 to run this script, but see comment on setting up IPv6-clients
 100 .Sq behind
 101 your 6to4 router for the
 102 .Sy rtadvd-start
 103 command!
 104 .Sh CONFIGURATION
 105 The default IPv6 configuration for an interface assigns a link-local
 106 address to it and sets the interface to receive router advertisements.
 107 No further configuration is necessary for basic functionality.
 108 However, various settings can be modified by using sysctl.
 109 .Pp
 110 The
 111 .Nm
 112 script reads its 6to4 configuration from a config file named
 113 .Pa 6to4.conf .
 114 The
 115 .Pa 6to4.conf
 116 file is in
 117 .Xr perl 1
 118 syntax, and contains several
 119 variables that can be tuned to adjust your setup.
 120 .Bl -tag -width start-rtadvd
 121 .It Sy in_if
 122 The inside interface. If non-empty, this interface is
 123 assigned the IPv6 address
 124 2002:x:x:v6_innernet:hostbits6, see below.
 125 This is only useful on machines that
 126 have more than one network interface, e.g. with a modem and a
 127 local ethernet.
 128 .It Sy v6_net
 129 The subnet address you want to use on the address of
 130 your outbound interface. Defaults to
 131 .Dq 1 .
 132 .It Sy v6_innernet
 133 The subnet address you want to use on the address of
 134 your inbound interface. Defaults to
 135 .Dq 2 .
 136 .It Sy hostbits6
 137 The lower 64 bits of both the inbound and outbound interface's
 138 addresses.
 139 .It Sy peer
 140 Name of the remote 6to4 server that'll take our
 141 IPv6-in-IPv4 encapsulated packets and route them on
 142 via IPv6. A special value of
 143 .Dq 6to4-anycast
 144 can be used for the anycast service defined in RFC 3068.
 145 Other possible values are given in the example config file.
 146 .El
 147 .Sh SEE ALSO
 148 .Xr stf 4 ,
 149 .Dq 6to4 IPv6 Explained
 150 at
 151 .Pa http://www.feyrer.de/NetBSD/6to4.html ,
 152 .Nx
 153 IPv6 Documentation at
 154 .Pa http://www.netbsd.org/Documentation/network/ipv6/ ,
 155 RFC 3068.
 156 .Sh HISTORY
 157 The
 158 .Nm
 159 6to4 utility and manpage portions were written by
 160 Hubert Feyrer <hubert@feyrer.de> for NetBSD.