New: RFC4193 IPv6 addresses seem not to be completly supported : default gateway not set

http://bugzilla.kernel.org/show_bug.cgi?id=9443

Summary: RFC4193 IPv6 addresses seem not to be completly
supported : default gateway not set
Product: Networking
Version: 2.5
KernelVersion: 2.6.22-3
Platform: All
OS/Version: Linux
Tree: Mainline
Status: NEW
Severity: normal
Priority: P1
Component: IPV6
AssignedTo: [email protected]
ReportedBy: [email protected]

Most recent kernel where this bug did not occur: unknown
Distribution: DEBIAN SID
Hardware Environment: tested on COMPAQ Deskpro EN and VMware Workstation Software Environment: reproduced in Kernel Version 2.6.22-14 (UBUNTU) Problem Description:

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". 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.

Steps to reproduce:

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:~#

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:~#