Problems with Smart DNS service and IP not matching/constantly changing

[EeK]

Hi, everyone,

I have an RT-AC86U running Asuswrt-Merlin's 384.13 firmware, with amtm, Diversion, Skynet and scMerlin scripts installed.

A few years ago, I signed up for a Smart DNS service (not VPN), by Getflix, to bypass geo-blocking restrictions imposed by certain streaming services, such as Netflix, Amazon Prime, HBO Now, etc.

I use DNS filtering to limit the Smart DNS to the specific devices where I stream TV shows and movies (currently, only my Apple TV 4K, since I've had issues with the Nvidia TV Shield, due to it having Google's DNS hardcoded into it).

I've never had any issues with that setup (other than the aforementioned problem with the Shield TV), but I didn't have amtm or any of the other scripts installed before. I noticed that since installing those, it's been quite difficult to get Getflix working even on the ATV4K, where it used to work flawlessly.

I found out that it's due to my IP (dynamic IP, provided by my ISP) constantly changing and, most of the times, not even matching the one displayed on Getflix's website, where I have to manually login and "update" the IP every time it changes, so that they can verify it.

Even though it's a dynamic IP, it only used to change every three or so months, or on the rare occasion of a power outage or some other situation that forced me to reboot my ISP's ONT (I have fiber) and my router.

Now, it's changing every 15-30 seconds, and, like I said, most of the times it doesn't even match what's being displayed on whatismyipaddress.com and Getflix's own website, for example.

Could this issue be caused by some of the scripts that I have installed? If so, how can I fix it?

I look forward to hearing from you. Thanks in advance.

Update with some extra information:

I've disabled Diversion and Skynet, for testing purposes, and the issue keeps happening, so it's definitely not related to those.

I also tested on my phone (iPhone X), on regular Safari (no extensions or anything), connected to the same network, and the behavior seems to be the same.

On the router's GUI, the WAN IP shown under "Network Map" is completely different than any of the other IPs (on either whatismyipaddress.com and Getflix's website).

If I click the globe icon, so that it displays the "Internet Status" side bar, there are two WAN IPs listed - none of them match any of the other ones. But they do remain the same, even after some time and several refreshes.

 

[ColinTaylor]

I've never had any issues with that setup, but I didn't have amtm or any of the other scripts installed before. I noticed that since installing those, it's been

... been what?

 

[EeK]

... been what?

Hey, Colin!

Sorry, I accidentally pressed something on my keyboard that ended up posting the thread before I was done writing.

I've edited it with the remaining information, if you don't mind taking another look.

 

[Ronald Schwerer]

Maybe ask your ISP why your IP changes so frequently. That (15-30 sec) seems very excessive.

 

[ColinTaylor]

Now, it's changing every 15-30 seconds, and, like I said, most of the times it doesn't even match what's being displayed on whatismyipaddress.com and Getflix's own website, for example.

What are you looking at to determine what the IP address is and how often it's changing? If it's really changing that often I would expect your internet to be next to unusable.

 

[EeK]

Maybe ask your ISP why your IP changes so frequently. That (15-30 sec) seems very excessive.

I've tried, but their support is useless. Their answer was that I have a dynamic IP and that it sometimes can change. They then offered to "upgrade" it to a static IP for basically double of what I'm paying now. They couldn't explain why it was changing every three months or so in the past, and it's now changing every 15-30 seconds.

What are you looking at to determine what the IP address is and how oftten it's changing? If it's really changing that often I would expect your internet to be next to unusable.

Well, I go to whatismyipaddress.com (or any other websites which display your IP) and see what's currently being shown. On the case of the aforementioned website, my IPv6 remains constant, whereas my IPv4 changes with pretty much every refresh.

Getflix has their own IP verification page in their dashboard, and even when it's updated, so that my current IP matches the registered one, the one displayed on other websites is different.

I have no issues with my internet connection, other than geoblocking not working on the ATV4K most of the time, due to the fact that my current IP ceases to match the one registered on Getflix.

 

[ColinTaylor]

Well, I go to whatismyipaddress.com (or any other websites which display your IP) and see what's currently being shown. On the case of the aforementioned website, my IPv6 remains constant, whereas my IPv4 changes with pretty much every refresh.

Getflix has their own IP verification page in their dashboard, and even when it's updated, so that my current IP matches the registered one, the one displayed on other websites is different.

What I mean is what are you looking at on the router to determine your public IP address? Does that match what you are seeing on whatismyipaddress?

If you're using IPv6 then maybe a rotating IPv4 address is normal? I don't know because I don't have IPv6.

 

[EeK]

What I mean is what are you looking at on the router to determine your public IP address? Does that match what you are seeing on whatismyipaddress?

If you're using IPv6 then maybe a rotating IPv4 address is normal? I don't know because I don't have IPv6.

Oh, do you mean the WAN IP?

Two are shown on the router's GUI, but none of them match the ones on Getflix's website or any of the other ones. The WAN IPs are completely different (all four blocks of numbers), whereas the rest only seem to differ when it comes to the last two blocks (usually changing by just a few numbers - either higher or lower than the previous one).

And I have no idea if a rotating IPv4 is normal. Like I said, until very recently, my IP only seemed to change every three months or so, or whenever I rebooted the ONT.

 

[EeK]

Also, I've disabled Diversion and Skynet, for testing purposes, and the issue keeps happening, so it's definitely not related to those.

I also tested on my phone (iPhone X), on regular Safari (no extensions or anything), connected to the same network, and the behavior seems to be the same.

Edit: Of note, my WAN IPs have not changed ever since I first checked them.

 

[ColinTaylor]

Edit: Of note, my WAN IPs have not changed ever since I first checked them.

So you're saying that your router's WAN IPs are not changing, only the public IP address presented by your ISP. That sounds like an ISP issue, like CGNAT perhaps.

Do you actually have IPv6 enabled on your router?

 

[L&LD]

@EeK, have you tried unplugging the router and the ONT and leaving them off for up to an hour, but at least 10 minutes? This may reset the connection the ONT has with your ISP and possibly fix the underlying issue instead of the symptoms you're seeing.

 

[EeK]

So you're saying that your router's WAN IPs are not changing, only the public IP address presented by your ISP. That sounds like an ISP issue, like CGNAT perhaps.

Correct.

Do you actually have IPv6 enabled on your router?

I do, yes. I just checked, and the "LAN IPv6 Prefix" matches the one displayed on whatismyipaddress - only the four blocks of numbers after that are different than what's shown as "LAN IPv6 Address" (that has only "1" listed).

@EeK, have you tried unplugging the router and the ONT and leaving them off for up to an hour, but at least 10 minutes? This may reset the connection the ONT has with your ISP and possibly fix the underlying issue instead of the symptoms you're seeing.

Hey, L&LD!

I've involuntarily left them both unplugged for several hours very recently (a few days ago), as I had a power outage that lasted for hours. It didn't seem to fix the issue, unfortunately.

 

[ColinTaylor]

I do, yes. I just checked, and the "LAN IPv6 Prefix" matches the one displayed on whatismyipaddress - only the four blocks of numbers after that are different than what's shown as "LAN IPv6 Address" (that has only "1" listed).

OK I'll have to bow out here as I don't have any experience with IPv6. But it sounds like IPv6 is working OK, whereby each individual client on your LAN has its own unique IPv6 address.

I don't know how IPv4 addresses work in your situation.

 

[EeK]

OK I'll have to bow out here as I don't have any experience with IPv6. But it sounds like IPv6 is working OK, whereby each individual client on your LAN has its own unique IPv6 address.

I don't know how IPv4 addresses work in your situation.

I've contacted my ISP yet again and requested to talk to some higher level support agent. They were only able to confirm that the WAN IP (the one that shows up on the router's GUI main page, under "Network Map") is, indeed, the one that they are providing. The guy had no idea what the secondary IP was (the one that shows up underneath the first WAN IP when you click the globe and the "Internet status" sidebar pops up).

Neither of those IPs is changing, so I assume that the behavior where it took a long time for my ISP's dynamic IP to change actually remains the same, and my router will only get a new IP after some time or after a reboot. I don't know why no service or website is able to see that IP, though. On any website, my IP looks completely different than the WAN IP. None of the number blocks match!

 

[L&LD]

@EeK, maybe a browser caching issue?

 

[ColinTaylor]

Try disabling IPv6 on the router completely (you'll need to reboot all your client devices) and run with only IPv4 for a while. See if that's the problem (having mixed IPv6/IPv4).

 

[dosborne]

A few years ago, I signed up for a Smart DNS service (not VPN), by Getflix, to bypass geo-blocking restrictions

If your ISP is reporting things are "normal", then I would suspect GetFlix. Have you tried disabling it to test? Although you say "not VPN", it is a VPN and could easily explain why your IP keeps changing externally.

 

[EeK]

Update: @ColinTaylor, you were right! I was reading about CGN/CGNAT yesterday, and it became clear, after checking out these two threads, that it was exactly what my ISP was doing.

So, I emailed them, in hopes of reaching someone who was actually knowledgeable, explained my situation and kindly asked if it was possible to revert my IPv4 to public, since Getflix has no support for IPv6.

Guess what? It worked! They contacted me today to inform that they had made the change, and I'm back to a (somewhat) stable IPv4.

Thank you all for the help, and especially to Colin, for the CGN/CGNAT suggestion.