Issue with too many DNS request

Hello,

I'm currently facing something "strange" in my opinion.

We're using 6.0.7 version with fortinet 60E device. (I was able to reproduce this one multiple times)

We have a log server that is configured with fqdn name. (meaning that the fortinet needs to resolve entry first to know at which IP the logs should be sent)

The connectivity is established (and possible) as soon as the VPN is built (from another front device - cisco one) meaning that the fortinet will be able resolving the fqdn log server when the vpn is up.

What I saw is that before the vpn is built, the fortinet is sending 100 000 dns request by minute trying to resolve the log name.

As soon as the VPN comes up, then the traffic is as expected.

The impact is that some old provider lines are droping packet and prevent the VPN establishement...

What I don't understand is why the fortinet is sending to many request ? even with the following dns configuration... (retry, timeout)

this is an example of our configuration :

================Log Configuration===================

config log syslogd setting     set status enable     set server "example.com" =============== DNS Configuration=================== config system dns     set primary W.X.Y.Y     set secondary W.X.Y.Z     set ip6-primary ::     set ip6-secondary ::     set timeout 5     set retry 2     set dns-cache-limit 5000     set dns-cache-ttl 1800     set cache-notfound-responses disable     set source-ip 0.0.0.0 end

Yoann