RFC4193 IPv6 addresses seem not to be completly supported : default gateway not set
Hello,
I made the following tests on ETCH and SID with the same result. I
tested on COMPAQ Deskpro EN and VMware machines (the captures below are
taken from the VMware machine) .
RFC4193 defines fc00::/8 and fd00::/8 IPv6 addresses known as "Local
IPv6 addresses" and stated that "They are not expected to be routable on
the global Internet" and "They are routable inside of a more limited
area such a site".
As you can see, RFC4193 addresses are the equivalent of RFC1918 IPv4
addresses for IPv6.
When using this kind of address as "static" (iface ... static), the
default gateway is not set (see the result of the command route -6 :
::/0 route is missing), so sending such IPv6 packets outside the local
LAN is not possible.
debian:~# cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
allow-hotplug eth0
iface eth0 inet dhcp
iface eth0 inet6 static
pre-up modprobe ipv6
address fd12:3000:4000:5000::1
netmask 64
gateway fd12:3000:4000:5000::100
debian:~#
debian:~# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0C:29:B8:53:3B
inet addr:192.168.19.135 Bcast:192.168.19.255
Mask:255.255.255.0
inet6 addr: fd12:3000:4000:5000::1/64 Scope:Global
inet6 addr: fe80::20c:29ff:feb8:533b/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:262 errors:0 dropped:0 overruns:0 frame:0
TX packets:141 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:28702 (28.0 KiB) TX bytes:20060 (19.5 KiB)
Interrupt:17 Base address:0x1080
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:560 (560.0 b) TX bytes:560 (560.0 b)
debian:~#
debian:~# route -6
Kernel IPv6 routing table
Destination Next Hop Flags Metric
Ref Use Iface
::1/128 :: U 0 4
1 lo
fd12:3000:4000:5000::1/128 :: U 0 0
1 lo
fd12:3000:4000:5000::/64 :: U 256 0
0 eth0
fe80::20c:29ff:feb8:533b/128 :: U 0 0
1 lo
fe80::/64 :: U 256 0
0 eth0
ff00::/8 :: U 256 0
0 eth0
debian:~#
I also tried to set net.ipv6.ip_forward=1 in sysctl.conf without success.
And adding the default route manually gives an error :
debian:~# route -A inet6 add ::/0 gw fd12:3000:4000:5000::100 eth0
SIOCADDRT: Invalid argument
debian:~#
=========================================================================
Now, with a "more common IPv6 address" : the ::/0 default route is active.
debian:~# cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
allow-hotplug eth0
iface eth0 inet dhcp
iface eth0 inet6 static
pre-up modprobe ipv6
address 2000:3000:4000:5000::1
netmask 64
gateway 2000:3000:4000:5000::100
debian:~#
debian:~# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0C:29:B8:53:3B
inet addr:192.168.19.135 Bcast:192.168.19.255
Mask:255.255.255.0
inet6 addr: 2000:3000:4000:5000::1/64 Scope:Global
inet6 addr: fe80::20c:29ff:feb8:533b/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:89 errors:0 dropped:0 overruns:0 frame:0
TX packets:76 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:9386 (9.1 KiB) TX bytes:11902 (11.6 KiB)
Interrupt:17 Base address:0x1080
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:560 (560.0 b) TX bytes:560 (560.0 b)
debian:~#
debian:~# route -6
Kernel IPv6 routing table
Destination Next Hop Flags Metric
Ref Use Iface
::1/128 :: U 0 6
1 lo
2000:3000:4000:5000::1/128 :: U 0 0
1 lo
2000:3000:4000:5000::/64 :: U 256 1
0 eth0
fe80::20c:29ff:feb8:533b/128 :: U 0 0
1 lo
fe80::/64 :: U 256 0
0 eth0
ff00::/8 :: U 256 0
0 eth0
::/0 2000:3000:4000:5000::100
UG 1 0 0 eth0
debian:~#
======================================================================
Does anybody have an idea about this issue ?
Best regards,
Guy Widloecher
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