Is anyone else having problems with a changing IP address?

ModernMarvel wrote:

MitchNC wrote:

I finally suffered through an hour-long call with T-Mobile.  They said there is no fix.  Our T-Mobile Home Internet routers jump back and forth between towers like a phone.  There will never be a fix, she said.

I asked why the problem just started for me a month ago.  She said the IP situation has always been like this but websites recently started cracking down due to security concerns.

 

As you know, their answer is not accurate.  I've had this service for almost 2yrs now and this problem only recently started.  I know prior to this that it held the IP for several days, even months, so long as you didn't reboot.  I can deal with the IP location always being states away, that's just an annoying.  This however, makes the service unusable for the work I must do from home as I can't complete authentications without the IP changing in the middle.  This is not normal behavior and sites see this as a possible security event (think man in the middle attack).

The support I talked to also tried to pass this off as normal.  They seem to now have a shared response to provide us.  They did let on something about "bands" and tower saturation being involved.  My guess is another poster is on to something that the change to 5G towers and infrastructure, along with more people, is contributing to T-mobile now having an architecture that is unable to manage the demand.

 

Btw, their recommendation for a google mesh router will not fix this problem unless that router is configured to utilize a VPN service that can stabilize your public side IP address.  You have to pay extra for that and adding a VPN overlay network on top can add additional latency, causing other problems.

 

This is a horrible development in an otherwise good service - especially for those of us in rural areas with no options.

t-Mobile if you guys follow this, yes, your current explanation is incorrect.   Otherwise networking would not work at all… for a TCP session/connection to work, the IP address must remain constant… otherwise the video streams would be constantly interrupted, and it would be non-stop disconnect chaos.  Your mobile phone technologies have solved this problem a long time ago with mobile IP and the ability to move an IP address around through towers as a persons endpoint changed location.

Note to people saying this is nature of the beast unless you have static IP.. Nope.  This is not dynamic vs static IP address problem.  Even with dynamic IP address your IP address will usually stay consistent for the entire time your device is connected to the network…. when you go to get your DHCP lease renewed, you will usually get the same IP address back.

This problem also appears to be somewhat related to the Minneapolis area, as many of the initial  complaints are from people in the Minneapolis area, or whos GEOIP location for their IP address maps to Minneapolis area.

My guess as to the source of the problem appears to be IPV6 to IPV4 Nat translation.  The bulk of our devices on mobile networks get an IPV6 Address (I do not know how to confirm this with my Nokia gateway as it does not appear to be presented in the app, even under diagnostic data.  My phone however gives both a IPV4 address (192.0.0.x) and an IPV6 address: 2607:fb90:Fa1C:xxxx:xxxx:xxxx:XXXX:XXXX 8 (My phone browser or hotspot has the same issue as the home internet gateway)
 

If I do a google search of sites to give me my IP address, there are of course  number of them. Open 5 to 10 of them up in different tabs in your browser and book mark the tab set.  Then close your browser.  Open the browser again, and open all tabs in the folder you saved the tab set to.   You will note that in spite of all of them opening within seconds of each other, most of them will tell you you are coming from a different IP address. 

My theory is that the device takes IPV6 connections from our device and translates it to an IPV4 address for transmission via IPV4 to the destination host, is taking the destination IP address into account in how it maps connections to IPV4 source addresses..   This means for every different destination IP address, the NAT function will potentially give you a different source address (your device address actually remains constant).   If you are going to a cloud based solution, there will be multiple destination addresses for that cloud based solution (DNS lookup will return multiple IP address, or change IP address returned with every query)  This means from one connection to the next your destination IP address will change,  and thus your source IP address will change.

Going back to the test before with multiple tabs, Take note of a reported IP address on a tab and reload it….. You will likely see you will end up with the same source IP address as it gave you the last time…. different from the rest of the tabs…. This is a clear symptom of this problem.

I believe this a misconfiguration of a core networking device in the Minneapolis t-mobile core or potentially a software bug unique to the Minneapolis infrastructure.

Cordialmente,

Mike