- Document $ipv6_cpe_wanif.

- Emphasize $ipv6_enable and $ipv6_prefer are deprecated.
- Add more detail descriptions about $ipv6_activate_all_interfaces.
- Add some more examples of $ifconfig_IF_ipv6.
- rtsold(8) and rtadvd(8) can be used even when ipv6_gateway_enable=NO now.

Approved by:	re (kib)

share/man/man5/rc.conf.5

@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 19, 2011
+.Dd September 13, 2011
 .Dt RC.CONF 5
 .Os
 .Sh NAME
@@ -1282,6 +1282,13 @@ ifconfig_ed0_name="net0"
 ifconfig_net0="inet 192.0.2.1 netmask 0xffffff00"
 .Ed
 .It Va ipv6_enable
+This variable is deprecated.
+Use
+.Va ifconfig_ Ns Ao Ar interface Ac Ns _ipv6
+and
+.Va ipv6_activate_all_interfaces
+if necessary.
+.Pp
 .Pq Vt bool
 If the variable is
 .Dq Li YES ,
@@ -1292,13 +1299,12 @@ and the
 .Va ipv6_activate_all_interfaces
 is defined as
 .Dq Li YES .
-.Pp
-This variable is deprecated.  Use
-.Va ifconfig_ Ns Ao Ar interface Ac Ns _ipv6
-and
-.Va ipv6_activate_all_interfaces
-if necessary.
 .It Va ipv6_prefer
+This variable is deprecated.
+Use
+.Va ip6addrctl_policy
+instead.
+.Pp
 .Pq Vt bool
 If the variable is
 .Dq Li YES ,
@@ -1311,19 +1317,45 @@ If the variable is
 the default address selection policy table set by
 .Xr ip6addrctl 8
 will be IPv4-preferred.
-.Pp
-This variable is deprecated.  Use
-.Va ip6addrctl_policy
-instead.
 .It Va ipv6_activate_all_interfaces
+.Pq Vt bool
+This controls initial configuration on IPv6-capable
+interfaces with no corresponding
+.Va ifconfig_ Ns Ao Ar interface Ac Ns _ipv6
+variable.
+Note that it is not always necessary to set this variable to
+.Dq YES
+to use IPv6 functionality on
+.Fx .
+In most cases, just configuring
+.Va ifconfig_ Ns Ao Ar interface Ac Ns _ipv6
+variables works.
+.Pp
 If the variable is
 .Dq Li NO ,
-all of interfaces which do not have the corrsponding
+all interfaces which do not have a corresponding
 .Va ifconfig_ Ns Ao Ar interface Ac Ns _ipv6
 variable will be marked as
 .Dq Li IFDISABLED
-for security reason.  This means only IPv6 functionality on that interface
-is completely disabled.  For more details of
+at creation.
+This means that all of IPv6 functionality on that interface
+is completely disabled to enforce a security policy.
+If the variable is set to
+.Dq YES ,
+the flag will be cleared on all of the interfaces.
+.Pp
+In most cases, just defining an
+.Va ifconfig_ Ns Ao Ar interface Ac Ns _ipv6
+for an IPv6-capable interface should be sufficient.
+However, if an interface is added dynamically
+.Pq by some tunneling protocols such as PPP, for example ,
+it is often difficult to define the variable in advance.
+In such a case, configuring the
+.Dq Li IFDISABLED
+flag can be disabled by setting this variable to
+.Dq YES .
+.Pp
+For more details of the
 .Dq Li IFDISABLED
 flag and keywords
 .Dq Li inet6 ifdisabled ,
@@ -1344,6 +1376,47 @@ This is the IPv6 equivalent of
 .Va network_interfaces .
 Normally manual configuration of this variable is not needed.
 .Pp
+.It Va ipv6_cpe_wanif
+.Pq Vt str
+If the variable is set to an interface name,
+the
+.Xr ifconfig 8
+options
+.Dq inet6 -no_radr accept_rtadv
+will be added to the specified interface automatically before evaluating
+.Va ifconfig_ Ns Ao Ar interface Ac Ns _ipv6 ,
+and two
+.Xr sysctl 8
+variables
+.Va net.inet6.ip6.rfc6204w3
+and
+.Va net.inet6.ip6.no_radr
+will be set to 1.
+.Pp
+This means the specified interface will accept ICMPv6 Router
+Advertisement messages on that link and add the discovered
+routers into the Default Router List.
+While the other interfaces can still accept RA messages if the
+.Dq inet6 accept_rtadv
+option is specified, adding
+routes into the Default Router List will be disabled by
+.Dq inet6 no_radr
+option by default.
+See
+.Xr ifconfig 8
+for more details.
+.Pp
+Note that ICMPv6 Router Advertisement messages will be
+accepted even when
+.Va net.inet6.ip6.forwarding
+is 1
+.Pq packet fowarding is enabled
+when
+.Va net.inet6.ip6.rfc6204w3
+is set to 1.
+.Pp
+Default is
+.Dq Li NO .
 .It Va ifconfig_ Ns Ao Ar interface Ac Ns _ipv6
 .Pq Vt str
 IPv6 functionality on an interface should be configured by
@@ -1360,16 +1433,37 @@ ifconfig_ed0_ipv6="inet6 2001:db8:1::1 prefixlen 64"
 ifconfig_ed0_alias0="inet6 2001:db8:2::1 prefixlen 64"
 .Ed
 .Pp
+Note that a link-local address will be automatically configured in
+addition to the configured global-scope addresses because the IPv6
+specifications require it on each link.
+The address is calculated from the MAC address by using an algorithm
+defined in
+.Rs
+.%T "RFC 4862"
+.%O "Section 5.3"
+.Re
+.Pp
+If only a link-local address is needed on the interface,
+the following configuration can be used:
+.Bd -literal
+ifconfig_ed0_ipv6="inet6 auto_linklocal"
+.Ed
+.Pp
+A link-local address can also be configured manually.
+This is useful for the default router address of an IPv6 router
+so that it does not change when the network interface
+card is replaced.
+For example:
+.Bd -literal
+ifconfig_ed0_ipv6="inet6 fe80::1 prefixlen 64"
+.Ed
+.Pp
 Interfaces that have an
 .Dq Li inet6 accept_rtadv
 keyword in
 .Va ifconfig_ Ns Ao Ar interface Ac Ns _ipv6
 setting will be automatically configured by
 .Xr rtsol 8 .
-Note that this automatic configuration is disabled if the
-.Va ipv6_gateway_enable
-is set to
-.Dq Li YES .
 .It Va ipv6_prefix_ Ns Aq Ar interface
 .Pq Vt str
 If one or more prefixes are defined in
@@ -2628,16 +2722,12 @@ If set to
 run the
 .Xr rtadvd 8
 daemon at boot time.
-.Xr rtadvd 8
-will only run if
-.Va ipv6_gateway_enable
-is also set to
-.Dq Li YES .
 The
 .Xr rtadvd 8
-utility sends router advertisement packets to the interfaces specified in
-.Va rtadvd_interfaces
-and should only be enabled with great care.
+utility sends ICMPv6 Router Advertisement messages to
+the interfaces specified in
+.Va rtadvd_interfaces .
+This should only be enabled with great care.
 You may want to fine-tune
 .Xr rtadvd.conf 5 .
 .It Va rtadvd_interfaces