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FQDN objects generate excessive amount of DNS queries

For those using "new" type FQDN objects - have you noticed or looked at DNS stats from the gateway? The other day our DNS guy asked us why one of our VS gateways was generating 25 million (!) DNS queries per day.

So had to dig into it. 

I can't say that we use FQDN objects excessively (~200 objects, all new type) but we still like them.

As for calculation, after enabling WSDNSD debug following was concluded:

  • each FQDN object will create 10 DNS queries every minute (not too sure why but all 10 are sent at the same time nearly)
  • each FQDN object then will be added prefix "www" and another 10 queries sent to DNS every mi minute
  • lastly each successful response will trigger reverse lookup

 

Numbers seem to add up:

(200 x 10 x 2) x 60 x 24 = 5.76M

If you now add rerverse lookups then 20M is not a surprise number.

Seems very inefficient design if you ask me. Would be interesting to hear from CP why there is a need for such excessive amount of DNS queries.

We are running R80.10 take 203 VSX + MDS

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Re: FQDN objects generate excessive amount of DNS queries

Re: FQDN objects generate excessive amount of DNS queries

Awesome, thanks heaps Martin!
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