Jabber Login Issues for Some T-Mobile Users – Possible IPv6 Conflict?

[dhoskins]

We've been running into a strange issue where some staff members can't log into Jabber.

The common factor seems to be that they all use T-Mobile as their personal carrier. However, it's inconsistent—not everyone with T-Mobile is affected. For example, one user with an iPhone on T-Mobile can log in just fine, while another with the same setup can't get in at all.

We've verified that all their Jabber accounts are set up correctly, so it's not an account issue. Our network is primarily IPv4, and the Expressways are configured for IPv4 only. If an IPv6 device attempted to reach the Expressway, would there be any network logs showing that attempt, given that the Expressway is set to IPv4 only?

[Jonathan Schulenberg]

T-Mobile famously runs an enormous Carrier-Grade NAT deployment to allow their customers access to the IPv4 Internet. You should see a connection attempt from a v4 address. The correct design is to enable IPv6 on Exp-E for MRA although I agree that it’s odd some clients work while others don’t.

Edit: Retracted the part that claims NAT is a problem with embedded layer three and four details; that applies to IPv4 NAT as well, so Exp-E is clearly able to handle it. Start with looking for a v4 connection attempt.

[dhoskins]

I forgot to mention a couple of things in my last post. I also have T-Mobile as my carrier, and I can’t log in either.

Another thing—right around Christmas break, our campus switched from using Microsoft to Infoblox for DNS management.

If my phone is on WiFi at home, I can log into Jabber just fine. But when I’m on 5G only, I put in my sso@companyname info, hit continue, and it sits on “Finding service” for about five seconds. Then, in red, it says “We don’t recognize your email address. Try entering it again or go to Advanced Settings to connect manually.”

If I click “Diagnose Error,” it spins for about five seconds while checking server reachability. Then next to “Error,” it says “Can’t connect to server” and lists one of our Call Manager servers as the one it can’t reach.

As mentioned before, it's only a handful of people that are having issues logging into Jabber over cellular only and from what I can gather so far, those users are using T-Mobile as their carrier.

I exported my Jabber log file. Are you very good at reading log files?

If I look at the network log on expressway-e, I dont see anything.