[Olsr-users] OLSR 0.6.8 on OpenWrt with ipv6 and kernel 3.18.x

[Henning Rogge]

Strange,

olsrd is already setting the "ipv6 only" flag.

See http://olsr.org/git/?p=olsrd.git;a=blob;f=src/linux/net.c;h=03f136b68254a751c4673a59a0037f76a3a57325;hb=master#l499

Do you see any error messages in the syslog when you are starting
olsrd with "setsockopt(IPV6_V6ONLY):" in them?

If not you might want to have a look at your build-environment...
"IPV6_V6ONLY" doesn't seem to be defined.

Henning

On Mon, Mar 16, 2015 at 8:43 AM, Henning Rogge <(spam-protected)> wrote:
> Wait,
>
> I remember that thing from Debian...
>
> Most likely the IPv6 socket also receives the IPv4-datagrams because
> of "legacy IPv4 support".
>
> can you look for files named "bindv6only" in the /proc/sys/net/ipv6
> subdirectories (most likely in conf/all and conf/<if>). If you set it
> to "true" the problem should disappear (and we know that my guess was
> right).
>
> In Olsrd2 I explicitly mark all sockets as "bindv6only" with a socket
> flag, but there might be a reason (beyond "someone forgot") to do this
> in olsrd.
>
> I will have a look at the code and will prepare a patch to test while
> you test the procfile entries.
>
> Henning
>
> On Mon, Mar 16, 2015 at 8:37 AM, Russell Senior
> <(spam-protected)> wrote:
>>>>>>> "Henning" == Henning Rogge <(spam-protected)> writes:
>>
>> Henning> Hi, typically "detected duplicate packet with seqnr" happens if
>> Henning> you either have a problem with your linklayer driver OR a bad
>> Henning> bridge configuration.
>>
>> Henning> Are "br-pub" and "ptp" somehow connected on one side or the
>> Henning> other side with a bridge?
>>
>> I ran strace on olsr with ipv6 on OpenWrt r44764 on an alix2 with kernel
>> version 3.18.8, as well as on kernel version 3.14.34.  It appear that
>> with both kernels, olsrd opens two sockets on each interface.  However,
>> with kernel 3.14 only one of the sockets call recvfrom to get incoming
>> data, while on kernel 3.18 both of the sockets do.
>>
>> Apparently, since the same UDP datagram is received on both sockets, it
>> sees the same seqno twice, hence the syslog message.
>>
>>
>> --
>> Russell Senior, President
>> (spam-protected)