[6bone] Problem with Autoconfiguration when using 802.1Qencapsulation
Carlos Alberto Barcenilla
barce@frlp.utn.edu.ar
Sun, 3 Nov 2002 23:09:03 -0300
Hi!
I'm using 802.1q with ipv6 in linux routers (see
http://www4.ipv6.frlp.utn.edu.ar) and address autoconfig works fine.
I think the problem is that forwarding shoul be disabled in order to use
stateless autoconfig, look at this example:
[root@chuky conf]# ip -6 addr sh vlan3
6: vlan3: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue
inet6 fe80::250:bfff:fe1b:e026/10 scope link
inet6 3ffe:38e1:200:3001::20/64 scope global
[root@chuky conf]# echo 0 > /proc/sys/net/ipv6/conf/vlan3/forwarding
A few seconds later vlan3 interface has a new autoconfigured address
[root@chuky conf]# ip -6 addr sh vlan3
6: vlan3: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue
inet6 fe80::250:bfff:fe1b:e026/10 scope link
inet6 3ffe:38e1:200:3001::20/64 scope global
inet6 3ffe:38e1:200:3001:250:bfff:fe1b:e026/64 scope global dynamic
valid_lft 2591994sec preferred_lft 604794sec
Regards
----- Original Message -----
From: "Nicolas DEFFAYET" <nicolas.deffayet@ndsoftware.net>
To: <enric@satec.es>
Cc: <6bone@ISI.EDU>
Sent: Sunday, November 03, 2002 7:31 PM
Subject: Re: [6bone] Problem with Autoconfiguration when using
802.1Qencapsulation
> 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
>
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