[Dnsmasq-discuss] RA support in dnsmasq

[Gene Czarcinski]

On 11/29/2012 02:08 PM, Gene Czarcinski wrote:
> 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.
>
Have you ever felt really sick on a Friday but decided to wait until 
Monday to see a Doctor and then, On Monday, when you see the Doctor 
neither he nor you can find anything wrong.

Well, I am not sure what was happening when I was getting all of those 
RTR-ADVERT messages but they appear to be "normal" now.

1. Only a few ra-unsolicited occurred.

2. Although they start out frequent it settles down to about once every 
none to ten minutes.

3. Starting another virtual network get the first one to get frequent 
again but, after a while, they both settle down to about nine minutes.

4. I have not noticed any stuff with the real (p33p1) NIC.

Note:

1. During the last month or so there have been some system updates 
including the kernel.

2. Also over the last month or two I have been running "leading edge" 
development versions of libvirt and NetworkManager.

Right now all I can do is let it run and keep an eye on it.

Gene