USG FLEX 500 - DNS white list doesn't work over the DNS general classification

GateArray

Ciao

I got a problem regarding wrong DNS classification.

A site of a customer as been classified as "phishing".

I put that dns on "DNS ALLOW LIST" section, but the block persist.

if i try the make a simple "ping" this is the FW response:

It seems that "DNS ALLOW LIST" is working properly.

USG FLEX 500

5.41(ABUJ.0) 2025-09

Any idea?

Zyxel_Melen

Hi @GateArray

Thos domain is classified as business.

Now, you should be able to access without issue.

PeterUK

Try the following by SSH or web console

ip dns server cache-flush
debug content-filter https-domain-filter cache flush

There is a DNS flush you can try in monitor > security Statistics > DNS content filter

Zyxel_Melen

Hi @GateArray

Thos domain is classified as business.

Now, you should be able to access without issue.