AT&T Tethering giving two different IP Addresses

[ricketty]

I have noticed over the past few days, that I am simultaneously getting two different ip addresses on my AT&T phone.

To be clear - this is at the same time, without forcing an ip change via airplane mode on/off.

I've used multiple ip echo services to confirm this:
- IPBurger (non-ssl enabled)
- ipecho.net (non-ssl enabled)
- astrill.com (ssl enabled)
- ipdb.at (ssl enabled)
- as well as my own servers through both ssl and non-ssl channels

What I'm seeing, is that I'll get a different IP depending on whether I'm connecting to an ssl enabled service or not.

SSL enabled services are always in agreement (ie 111.111.111.111)
Non-SSL services are also always in agreement (ie 222.222.222.222)

If I turn airplane mode on/off to force an ip change, both addresses change.

Has anyone else seen this before?

[MM78]

What IP do you get when you go to IPBurger.com ?

[ricketty]

MM and I have PM'd back and forth a couple of times on this since his post. I wasn't sure I understood his question and was hesitant to post less masked ip addresses on the forum.

I've also been talking with a good friend that works for another carrier and learned that all Sprint devices are assigned two different IP addresses at all times. A primary and a secondary... the primary is the workhorse while the secondary kicks in if the primary stops responding for any reason.

I'm thinking that AT&T may have their network implemented a little differently where the primary is utilized for regular, non-SSL, web traffic (http / not encrypted) while the secondary handles SSL (https / encrypted) traffic.

I realize this may seem like over analyzing, but I'm not convinced that there's nothing more to see here.

ebay utilizes both encrypted and unencrypted connections, depending on the nature of your current activity.
- Registering for a new account or editing account details (anything with personal information involved) and you're on an encrypted (SSL) connection with ebay.
- Browsing items or even listing an item, you're on an unencrypted (non-SSL) connection.

Any device that is regularly using two ip addresses depending on the type of connection would be revealing both to ebay through the course of the session.

As for paypal, all paypal traffic seems to be encrypted (SSL).

[yankee]

I regularly get two IP addresses. One called Public and another called Cellular. Is this what you are talking about?

[ricketty]

Originally Posted by yankee

I regularly get two IP addresses. One called Public and another called Cellular. Is this what you are talking about?

How are you seeing the name on them?

The only reason I even came across this is that I've set up a few pages on my server to manage stealth profiles and log ip's used and noticed that my own server was reporting two different ip's for my browsing history simultaneously.

Initially I thought it was just my server, load balancing or something similar manged by the host. I kept digging and came to realize the two addresses were independently dedicated to either SSL or non-SSL requests, which I then confirmed by locating a dozen ip echo services to verify other servers were seeing the same thing and that it wasn't just mine.

I've read that some of the mifi's have issues with switching ip addresses after a short period... possible this could be related to that as well.