Network Blocking Encrypted DNS Traffic

[FilterPro]

I have a filter software that I place on iPhone in form of a DNS Profile. The DNS profile is necessary for my customers needs so removing it is not an option. Recently, customers have been reporting that when they got a new Verizon Fios router, they are not able to use their iPhone on the wifi, only on  cell phone data. When connected to the FiOS Wi-Fi they get the following message in the iphone settings under wifi:

Privacy Warning

This network is blocking encrypted DNS traffic

The names of websites and other servers your device accesses on this network may be monitored and recorded by other devices on this network

Please help! I really need guidance solving this issue.

[smith6612 · Accepted solution]

If I'm not mistaken, iPhone uses DNS over HTTPS for the Encrypted HTTPS service. It might be an issue with the McAfee Home Network Protection feature on the Verizon routers. Any chance you could ask someone to try turning off the feature in their My Verizon account to see if the problem is resolved?

https://www.verizon.com/support/residential/internet/essentials/home-network-protection

Alternatively, if they have Parental Controls or Application Restrictions enabled on their FIOS accounts/Routers, have them turn off the features. A lot of parental controls features on routers perform filtering by DNS, and may have to block Encrypted DNS services to enforce the rules. Alternatively, they can try adding an exclusion into the Parental Controls for your encrypted DNS profile, however this will likely come at the expense of parental controls not working at all.