I'm seeing quite a lot of messages logged in the syslog output from my PA VM-100 running PAN-OS 10.0.0:
Aug 19 07:31:29 firewall-1 1,2020/08/19 07:31:29,007051000047085,SYSTEM,general,2560,2020/08/19 07:31:29,,general,,0,0,general,medium,"DNS signature lookup timed out",1461969,0x0,0,0,0,0,,firewall-1,0,0,1970-01-01T10:00:00.000+10:00
What exactly does "DNS signature lookup timed out" mean?
My VM has two local DNS servers configured, which are functioning well and the PA VM has access to do direct external lookups as well if it needs to do so. It is located on the end of a quiet 250/100M internet fibre connection here in Australia, so connectivity and congestion is not an issue.
The DNS Signature Lookup Timeout (ms) value is set to 300 - far far above what should be necessary.
Can anyone explain the traffic flow that might cause this (do these DNS queries go direct, or via configured resolver, and over what transport) ?
If this is an error, how do I go about debugging it to find the root cause?