[6bone] Problem with Autoconfiguration when using 802.1Q encapsulation

[Nicolas DEFFAYET]

On Sun, 2002-11-03 at 22:18, Enric Corominas i Bosch wrote:
Dear Enric,

> I'm trying to configure a Debian host as an IPv6 firewall. I have just one ethernet card, so I've been playing with
> 802.1Q, configuring three let's call "subinterfaces".
> 
> I use the software from candelatech (http://www.candelatech.com/~greear/vlan.html) to create the subinterfaces, and everything seems to work fine, the interfaces creates link local addresses, they are recognized by the switch, and the communication is fine.
> 
> Also I can give the subinterfaces an IPv6 address, and announce it with "radvd" (latest version, 0.7.2). 
> 
> >=======================================>
> almodis:/home/enric/vlan/vlan# ifconfig
> eth0      Link encap:Ethernet  HWaddr 00:00:E8:79:C0:43  
>           inet6 addr: fe80::200:e8ff:fe79:c043/10 Scope:Link
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:140467 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:6546 errors:36 dropped:0 overruns:0 carrier:72
>           collisions:623 txqueuelen:100 
>           RX bytes:10607455 (10.1 MiB)  TX bytes:1022885 (998.9 KiB)
>           Interrupt:5 Base address:0xe400 
> 
> eth0.2    Link encap:Ethernet  HWaddr 00:00:E8:79:C0:43  
>           inet addr:213.164.61.200  Bcast:213.164.61.255  Mask:255.255.255.192
>           inet6 addr: fe80::200:e8ff:fe79:c043/10 Scope:Link
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:36645 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:6497 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:0 
>           RX bytes:3711593 (3.5 MiB)  TX bytes:1002537 (979.0 KiB)
> >=======================================>
> 
> 
> But I've detected that the interface is not able to autoconfigure when receiving an "Router Advertisement"
> The RA is received correctly, but is ignored.
> 
> 
> >=======================================>
> Router advertisement from fe80::230:94ff:fe0a:b420 (hoplimit 255)
> Received by interface eth0.2
>         # Note: {Min,Max}RtrAdvInterval cannot be obtained with radvdump
>         AdvCurHopLimit: 64
>         AdvManagedFlag: off
>         AdvOtherConfigFlag: off
>         AdvHomeAgentFlag: off
>         AdvReachableTime: 0
>         AdvRetransTimer: 0
>         AdvSourceLLAddress: 00 30 94 0A B4 20 
>         Prefix 3ffe:400a:0:803::/64
>                 AdvValidLifetime: 2592000
>                 AdvPreferredLifetime: 604800
>                 AdvOnLink: on
>                 AdvAutonomous: on
>                 AdvRouterAddr: off
> >=======================================>
> 
> 
> I have looked into "/proc/sys/net/ipv6/conf/eth0.2", and "accept_ra" is set to "1", it is TRUE, so it should autoconfigure to the received prefix.
> 
> If I try to set the value to "1" or "0" by hand using "sysctl", it gives a syntax error, as it seems not to recognize the "." in the name of the interface, changing it for a "/"
> 
> 
> >=======================================>
> almodis:/proc/net# sysctl -w net/ipv6/conf/eth0.2/accept_ra=1
> error: 'net/ipv6/conf/eth0/2/accept_ra' is an unknown key
> almodis:/proc/net# 
> >=======================================>
> 
> This make me think of a kind of bug, but I can't imagine how to resolve it.
> 
> Another point I have seen is that the LINK LOCAL address has the same value in both "eth0" and "eth0.2", I don't know if this can have any relation with the ignoring of the router advertisement.
> 
> Any one has tried a similar configuration ? Any ideas ?

Autoconfiguration don't work probably because you have 2 interfaces with
the same MAC address.

In the USAGI mailing-list
(http://www2.linux-ipv6.org/ml/usagi-users/msg00832.html), YOSHIFUJI
Hideaki wrote:
"It seems that we should modify something to support IPv6."

802.1Q VLAN implementation for Linux need modification for support IPv6
?


Best Regards,

Nicolas DEFFAYET