[support] DAD Delay too high?

[Arnaud Ebalard]

Hi,

support at adhari.de writes:

> I performed the same tests on a fresh installed System (debian /kernel 2.6.31)
> Only MIP6 Support without NEMO or MCOA patches.I still have too high
> DAD delays (delay between the first Neighborhood Solicitation and the
> HomeAgent registration.) 
>
> I made about 300 tests and had an average value of 2,95 seconds.
>
> Look at this case for example:The first Neighbor solicitation was sent
> at time 12.556429 and the Binding update more than 3 seconds later at
> 15.920365 
>
> Any Idea?

Maybe. Are you using Debian unstable radvd > 1.2 (probably 1.3) which is
broken. See the discussion here:

http://lists.litech.org/pipermail/radvd-devel-l/2009-July/thread.html

> 00:59:10.856905 fe80::201:2ff:fe1a:d2be -> ff02::1      ICMPv6 Router advertisement
> 00:59:10.859420           :: ->ff02::16     ICMPv6 Multicast ListenerReport Message v2
> 00:59:10.947435           :: ->ff02::2      ICMPv6 Router solicitation
> 00:59:10.948423           :: ->ff02::16     ICMPv6 Multicast ListenerReport Message v2
> 00:59:11.369853  2001:a:b::1 ->2001:a:b::1000 ICMPv6 Echo request
> 00:59:11.370763 2001:a:b::1000 -> 2001:a:b::1  ICMPv6 Echo reply
> 00:59:11.528376           :: ->ff02::1:ff1d:b521 ICMPv6 Neighbor solicitation
> 00:59:12.454521           :: ->ff02::2      ICMPv6 Router solicitation
> 00:59:12.537394 fe80::201:2ff:fea7:a651 -> ff02::1      ICMPv6 Router advertisement
> 00:59:12.537802 fe80::201:2ff:fea7:a651 -> ff02::1      ICMPv6 Router advertisement
> 00:59:12.538302 fe80::201:2ff:fea7:a651 -> ff02::1      ICMPv6 Router advertisement
> 00:59:12.538851 fe80::201:2ff:fea7:a651 -> ff02::1      ICMPv6 Router advertisement
> 00:59:12.539392           :: ->ff02::16     ICMPv6 Multicast ListenerReport Message v2
> 00:59:12.539418 fe80::201:2ff:fea7:a651 -> ff02::1      ICMPv6 Router advertisement
> 00:59:12.556429           :: ->ff02::1:ff1d:b521 ICMPv6 Neighbor solicitation
> 00:59:12.630719           :: ->ff02::2      ICMPv6 Router solicitation
> 00:59:13.148431           :: ->ff02::1:ff1d:b521 ICMPv6 Neighbor solicitation
> 00:59:13.370432  2001:a:b::1 ->2001:a:b::1000 ICMPv6 Echo request
> 00:59:13.618430 fe80::216:6fff:fe1d:b521 -> ff02::16     ICMPv6 Multicast Listener Report Messagev2
> 00:59:14.370462  2001:a:b::1 ->2001:a:b::1000 ICMPv6 Echo request
> 00:59:15.370475  2001:a:b::1 ->2001:a:b::1000 ICMPv6 Echo request
> 00:59:15.916589 fe80::201:2ff:fea7:a651 -> ff02::1      ICMPv6 Router advertisement
> 00:59:15.917068 fe80::201:2ff:fea7:a651 -> ff02::1      ICMPv6 Router advertisement
> 00:59:15.917439 fe80::201:2ff:fea7:a651 -> ff02::1      ICMPv6 Router advertisement
> 00:59:15.917936 fe80::201:2ff:fea7:a651 -> ff02::1      ICMPv6 Router advertisement
> 00:59:15.918380           :: ->ff02::16     ICMPv6 Multicast ListenerReport Message v2
> 00:59:15.920365  2001:a:b::1 ->2001:a:b::1000 MIPv6 Binding Update

In fact, the BU is triggered 0.01 sec after receiving the RA (one in
the set of 4 RA).

I was hit by that same bug last week. I reinstalled downgraded my radvd
to version 1.2.

Cheers,

a+