[LEDE-DEV] umdns: query response only every 60s

[John Crispin]

On 26/09/17 16:51, Cristian Morales Vega wrote:
> On 26 September 2017 at 15:41, Philipp Meier <philipp.meier at neratec.com> wrote:
>> Hi
>>
>> When using umdns I experience the follow not expected behavior:
>>
>> There is no mDNS response sent for a service where an announcement or a
>> response has been sent in the last 60 seconds (see service.c function
>> service_timeout).
>>
>> 1. I started the LEDE device
>> 2. Then I started a PC application
>> 3. In the PC app I sent out an mDNS query
>> 4. I wondered why I did not get a response
>>
>> Then by looking at the source code I detected the service_timeout function
>> in service.c and now see that when I wait long enough with above step 3,
>> then I get the expected response from LEDE.
>>
>> In the mDSN RFC I cannot directly see any such requirement. But I might
>> interpret it wrong.
>>
>> Why is LEDE umdns only answering queries for a certain service every 60s?
> FWIW I have had the same problem ->
> http://lists.infradead.org/pipermail/lede-dev/2017-April/007188.html
>
> John did mention that the RFC says it's required, but I have never
> been able to find that reference.
>
i recall vaguely that there was some info in the rfc explaining how to 
mitigate flooding the network with lots of queries. i'll try to find 
that text snippet. if i cant find it i'll merge the patch.

     John