[Dnsmasq-discuss] RA support in dnsmasq

[Simon Kelley]

On 25/11/12 18:39, Gene Czarcinski wrote:
> On 11/25/2012 01:10 PM, Vladislav Grishenko wrote:
>> Hi Gene,
>> Instead of deprecating/turning-off logging by facility, it would be
>> better
>> to have ability to tune loglevel for each sysbsystem.
>> Like following: where 0 means
>> log-level=dhcp,dhcpv6,6,dns,7,ra,-1
>>
>> Best Regards, Vladislav Grishenko
> Yes, that is indeed a good idea,
>
> I have no intention of deprecating logging but I also do not want a
> large amount of information-less clutter in the syslog which may hide
> something that is important. The "RTR-ADVERT" messages being issued
> every 3 to 5 seconds with separate messages for each virtual interface
> that is started is a bit much.

But they're only that frequent for the first minute. After that they're 
every 10 minutes, I think.
>
> I have taken a look at the code and (I hope) I just do not understand
> how things are really working.
>
> If log-dhcp is specified (command line or conf-file), OPT_LOG_OPTS is
> set. A little grepping resulted in rfc3315.c and rfc2131.c as issuing
> messages with log6_packet() and log_packet() respectively. Sounds good,
> the test can be done in a central place. But, looking more closely, the
> only thing OPT_LOG_OPTS does is determine the form of the syslog message
> ... not if it is being issued. And, of course, there are other calls to
> my_syslog() scattered throughout.
>
> BTW, warning or at least error message should always be issued. It is
> all the info massages that are becoming overwhelming.
>
> Certainly there should be a lot of messages to support debugging and the
> code should always be compiled in. But, when things are working well it
> is better to have most of those messages inhibited so that some warning
> or error message will be seen.


I see the RTR_ADVERT messages as being equivalent to the logs of DHCP 
request and replies - they are at a minimum level which allows tracking 
of the history of interaction with a client. The DHCP logs, at least 
have equivalents in most DHCP servers.

It's important to know which prefixes are being advertised, since that's 
a function of quite a lot of configuration: not just dnsmasq config, but 
kernel-level interface configuration too.

Cheers,

Simon.




>>>>
>>>> 3. Similar to radvd, should there be some dnsmasq parameters which are
>>>> used to specify how often RAs will be issued?

There could be, but only if it makes sense to tune that for network 
performance, not just prettifying the logs. The philosophy in dnsmasq 
has always been to hide useless tuning settings and try and let people 
configure what they want to do, not control every field of every packet. 
I be no-one uses that option in radvd