[Dnsmasq-discuss] RA support in dnsmasq

Gene Czarcinski gene at czarc.net
Thu Nov 29 19:08:43 GMT 2012


On 11/29/2012 11:28 AM, Simon Kelley wrote:
> On 29/11/12 16:06, Gene Czarcinski wrote:
>
>> Something is definitely not working correctly.  I do not know if you
>> have a qemu/kvm setup so duplicating the conditions that way will not work.
>>
>> Attached is a piece of syslog (before I patched things to suppress the
>> messages).  BTW, I also have no idea why anything is being done with
>> "p33p1" ... that is the real NIC on that system.  I have also attached
>> the dnsmasq conf file for that interface.
>>
>> I am willing to try any testing.  Unless I can get things to work as
>> they are suppose to, user reception of using dnsmasq to handle RA will
>> get support somewhere between zero and none :-)
> Another theory: a netlink NEWADDR event (ie assigning an address to a
> network interface) triggers the one minute of rapid advertisements.
> Maybe something on your system is doing that regularly?
>
> Can you try adding a logging line next to the call to
> ra_start_unsolicited() in nl_async() in netlink.c, to see how often that
> gets called?
>
>
OK, rebuilt dnsmasq with the patch to limit RTR-ADVERT out and a patch 
added to issue a syslog message when ra_start_unsolicted is done.  It is 
installed on two systems which also run virtualization.  They are both 
fairly new AMD-cpu systems and I have not had any problems with clocks.  
One virtual network started on each and no other dnsmasq instances.

I do wonder if this rapid issuing also takes place with radvd but has 
never been noticed because it does not issue log messages.

BTW, on a system which does not have virtualization installed (because 
it cannot run it) but does have dnsmasq doing its thing including 
DHCPv6, there are RTR-ADVERT messages about every eight minutes per 
interface.

Gene



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