host trying to connect using IPv6 without having IPv6 global address

[Γιώργος Πάλλας]

Mark Kamichoff wrote:
> On Tue, Mar 02, 2010 at 11:50:09PM +0200, Γιώργος Πάλλας wrote:
>   
>> It sits behind an ordinary adsl router, with no IPv6 capabilities, it
>> gets its private 192.168.x.x address etc.
>>
>> Now the problem is that it tries to connect to hosts returning quad-A
>> records using IPv6, but it has no IPv6 global address. Ifconfig shows
>> only  the normal 'link' IPv6 address. So, eventually it does not connect.
>>
>> For example, using the browser I can't go to http://www.ipv6.org
>>
>> Aptitude update stalls, writing:
>>
>> 84% [Connecting to security.debian.org (2001:610:1908:a000::149:225)]
>>
>> Or even:
>>
>> $ telnet security.debian.org
>> Trying 2001:610:1908:a000::149:225...
>>
>> I would appreciate any help, because this problem starts to get me!
>>
>> Below, in the bz2 file, I give a transcript of various useful command
>> outputs, if someone bothers to dive into it! I include a telnet strace,
>> netstat IPv6 output, ifconfig, my IPv6 routing table, and other things.
>> Something I suspect is this entry in my routing table:
>> ::/0                           fe80::4432:f215:1283:2320  UGDAe 1024
>> 0    90 eth2
>>
>> should that be there?
>>     
>
> This is the problem.  Issue an "ip -6 route del default" and you should
> be all set.
>
> I suspect at some point your host accepted an RA packet (possibly with
> the 'M' flag set, which may explain the lack of an autoconfigured global
> address) and set the default route to the LL address of the advertising
> router.
>
> - Mark
>
>   

You were right!

I deleted the route, and all was OK - until 10 minutes later that the
route reappeared! I deleted it again and it reappeared once more. I then
set up tcpdump running and checked the packets I received when the route
reappeared. So I discovered something interesting.

This is the packet that was setting up the route:

20:30:25.828992 IP6 fe80::4432:f215:1283:2320 > ff02::1: ICMP6, router
advertisement, length 32

My adsl router did not have such a mac address, so I checked my wife's
laptop which is running the evil Windows 7. I found out that the
wireless interface had the address fe80::4432:f215:1283:2320 as link
local, and was sending in a 7-10 minutes interval this router
advertisement...

This advertisement comes among other messages related to IPv6 (in the
following, fe80::222:5fff:fe6e:cc63 is my debian's laptop link local
address on the wireless interface):

19:49:12.259649 IP6 fe80::222:5fff:fe6e:cc63 >
fe80::4432:f215:1283:2320: ICMP6, neighbor solicitation, who has
fe80::4432:f215:1283:2320, length 32
19:49:12.263671 IP6 fe80::4432:f215:1283:2320 >
fe80::222:5fff:fe6e:cc63: ICMP6, neighbor advertisement, tgt is
fe80::4432:f215:1283:2320, length 32
19:49:17.294542 IP6 fe80::4432:f215:1283:2320 >
fe80::222:5fff:fe6e:cc63: ICMP6, neighbor solicitation, who has
fe80::222:5fff:fe6e:cc63, length 32
19:49:17.294571 IP6 fe80::222:5fff:fe6e:cc63 >
fe80::4432:f215:1283:2320: ICMP6, neighbor advertisement, tgt is
fe80::222:5fff:fe6e:cc63, length 24
19:49:55.387376 IP6 fe80::4432:f215:1283:2320 > ff02::1: ICMP6, router
advertisement, length 32

Anybody else has heard of this win 7 behavior?

G.


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