[Dnsmasq-discuss] dnsmasq and RA

[Gene Czarcinski]

On 11/01/2012 08:59 AM, Gene Czarcinski wrote:
> On 10/31/2012 04:41 PM, Gene Czarcinski wrote:
>> Instead of running both radvd and dnsmasq, I would like to run only 
>> dnsmasq and have it do what is now being done by radvd.
>>
>> This is for libvirt so there are some specifics which could help.
>>
>> 1. There will be one and only one interface for an instance of dnsmasq.
>>
>> 2. Currently (at least with some patches I have created) run one ipv4 
>> dhcp subnetwork or one ipv6 dhcp supnetwork or both one ipv4 network 
>> and one ipv6 network.
>>
>> 3.  If a dhcp-range is specified for the ipv6 subnetwork then I need 
>> the AdvManagedFlag on which (I believe) is done with the additional 
>> dsnmasq parameter "enable-ra".
>>
>> 4.  But, I may have an IPv6 subnetwork but dhcp-range has not been 
>> specified.  In this case I want the AdvManagedFlag off. This one is 
>> the situation that I am not clear on.
>>
>> 5.  None of the other dnsmasq capabilities with respect to RA will be 
>> used.
>>
>> Comments/suggestions?
>>
>> If this requires a little enhancement patch, I am willing.
>>
>>
> OK, I believe I have answered my own question but I would still like 
> confirmation.
>
> I ran a test with no radvd running ... only dnsmasq.  With enable-ra 
> and dhcp-range specified for ipv6 addresses, the client side gets a 
> dhcp6 address and RA default route.  With enable-ra and NO dhcp-range 
> specified, the client gets a SLAAC address and RA default route.
>
> With enable-ra and dhcp-range,I do notice a lot of RTR-ADVERT messages 
> ... like one every couple of seconds.  Is there a way to suppress this 
> message and/or increase the time between the events or at least the 
> messages [that is without disabling dhcp logging] ?
>
> Maybe it would be useful is this message was only sent to the syslog 
> once every ten or twenty events.
>
One additional question  With enable-ra and dhcp-range, then dnsmasq 
supplies the RDNS info in the RA packet but it does not if dchpv6 is not 
specified.  It seems like this should be reversed.

Gene