The curious case of DNS

A couple of weeks ago, at my $dayjob, we implemented a recursive resolver with RPZ in an enterprise network. After a few days, the customer got back to us with an issue - the DNS resolution of the domain failed with an NXDOMAIN response. After a cursory look at the problem, it became evident that resolved correctly but did not. The customer also reported that if they switched the resolver to 8.

Jio VoWiFi issue - It's always DNS!

tl;dr If Jio VoWiFi isn’t working for you, set a different DNS resolver on the phone. While I am a big proponent of running your own resolver in the network, ( ) , you could test by using open resolvers. The issue doesn’t seem to be impacting everyone and only a subset of users. To begin with, there are multiple things broken in the authoritative name servers and ns2.

Chromium based browsers & DNS

While this is not something new, it perhaps has more significance because of the ever increasing market share of more than 60% of Chromium based browsers. Chromium based browsers have a very uncanny method to check if the web browser is sitting behind a captive portal. And if you’re running a recursive resolver in your network with a large user base running Chromium based browsers (Google Chrome, Brave etc), it might even startle you if you observe the recursive resolver logs.