Every morning, I do a multiple DNS Leak test just as a precaution. Today, I did the leak test and all my IPs were different. They were the same IP block, just different. This made me suspicious and I set about trying to track the problem down. Turns out, there was a misconfiguration in the VPS. Worked yesterday, different today. I guess it was ghosts or gremlins in the machinery.
I got to thinking, for you guys who download a lot of Linux ISOs, might be a good idea to check daily. Even though you are setting behind a VPN, it’s still worth the minute it takes to fire off multiple DNS Leak checks just for a sanity check.
I might be misunderstanding, but you’re checking what exactly for DNS leaks?
If the IPs are changing, that’s not uncommon. The HOST changing would be though, like if you swapped from what you expected back to Comcast or something.
You need to get better control of your local network and not have to be paranoid about this. Static reservations for long lived hosts, your router should have a setting to override and prevent internal hosts (like guests) from sending OoB DNS requests, and any sort of VPS stack should as well.
Maybe a picture will help. This one is from Browserleaks:
Where the IP is listed at the top of the page. All the last numbers in the IP sequence were different. Same block, still piped through Cloudflare tho.
Your public IP is DHCP. It changes from time to time. Nothing weird about that.
Any of the other IP’s in the DNS Servers list changing is just what you get pointed to when resolved based on your GeoIP location.
Hmmmm I seem to be unable to explain.
Ok. Fire up the VPN.
Do, 4 different, simultaneous, leak checks from multiple sites like Browser Leaks, dnscheck.tools, etc.
As in the picture, under ‘Your IP’. Results:
Whereas xxx.xxx.xxx stayed the same, but the last set in the sequence was different in every test. The IP block (xxx.xxx.xxx.) was the same, just the last three digits were different in 4 different, simultaneous, tests. I realize VPN IPs change and so do Cloudflare IPs change. What I am saying is tho the IP block was the same (owned by the VPN), just the last three digits were different, even when I changed locales in my VPN.
I hope that explains what I’m trying to say.
See my other response. This is quite normal.
They have always been the same, now for years.
Then something has changed about the local deployment and concentration of the network near you. Don’t know what to tell ya 🤷
As long as the provider is the same, and your instances are using properly using DoH or DoT, you have nothing to worry about.
If you’re super concerned though, I’d be using Mullvad over Cloudflare though. Just saying.
Each different DNS leak test sites (multiple), were different, yet the same IP block. I don’t view it as paranoia. When you fire up your VPN, even though you have specified a certain locale, say Mexico, you still get different IPs each time you start your VPN, at least I do.
Example: 4.4.4.5, 4.4.4.6, 4.4.4.15
Same block, different IPs reported.
Yes, that’s called Round-Robin Load Balancing.
To get more specific, your DNS provider spins up a large number of DNS resolvers out in the world on a CDN network that resolves clients to the most geographically convenient server(s) at any point in time based on the GeoIP info of your public IP.
Once you resolve one set of addresses at any given time, it caches your request, so the next time you ask these DNS servers for something you’ll get a response right back from them as fast as possible.
You constantly checking is just going to show this. It’s quite normal.
I’ll have to accept a higher knowledge base than mine, but I check this every morning, and for years they have been the same across different leakcheck sites.