macOS v15.6.1 update seems to break networking on the Simulator

Question

Created 6d

Replies 3

Boosts 0

Participants 2

Around 8/23/25, I installed macOS 15.6.1 on my work Mac. After this I can no longer log the application I am working on into our backend servers. My work Mac is running Palo Alto Global Protect VPN software along with a bunch of associated security software to lock down my computer. I had no issues with connecting to our backend servers behind the firewall before the macOS update and nothing has changed in the source code related to this. When I send the username the network call just hangs and never times out.

On the other hand, if I turn off the VPN and point to the production environment the call succeeds with no problems.

Any Ideas?

Answered by DTS Engineer in 857080022

OK.

That fact that you have problems with macOS’s built-in curl means that this is neither:

A simulator issue
Nor a code-level issue

I think you’ll need to work with your VPN and API server admins to work out why this is failing [1]. My focus is on APIs, and you haven’t even got to that point )-:

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

[1] You could also ask about this over in the Apple Support Community, run by Apple Support, and specifically in the Business and Education topic area, where you’re more likely to find folks with relevant experience. However, it’s possible that they won’t be able to help either, because this seems to be very tightly bound to your specific network setup.

Boost

Answer 1

DTS Engineer OP

Apple

5d

In general, the simulator uses the macOS networking stack. Given that, it will be affected by changes to macOS, including the macOS VPN configuration.

As a first step I recommend that you try reproducing this on the macOS side, without the simulator:

If your back-end server is using HTTP[S], find a URL that fails in the simulator and try fetching that using curl from Terminal.
If you’re back-end server is using some other protocol, you may be able to do the same thing using nc.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

0

Answer 2

thomasfromboulder OP

2d

Hi Quinn!

Here is the curl call and the response:

https://xxx.yyy.com/bep/recovery/v2/accountStatus/abcd?OSVersion=ios_17.5&brandName=BRANDNAME&channelId=&clientAppName=com.company.company-native-myaccount&clientAppType=FULL&clientAppVersion=24.02.2025&deviceId=&deviceModel=iPhone&language=ENG&sourceSystem=APP&subBrandName=BRANDNAME

Host xxx.yyy.com:443 was resolved. * IPv6: (none) * IPv4: x.x.x.x * Trying x.x.x.x:443... * ALPN: curl offers h2,http/1.1 * TLSv1.3 (OUT), TLS handshake, Client hello (1): * Recv failure: Connection reset by peer * TLS connect error: error:00000000:lib(0)::reason(0) * OpenSSL SSL_connect: Connection reset by peer in connection to xxx.yyy.com:443 * closing connection #0 curl: (35) Recv failure: Connection reset by peer

This is using Palo Alto Global connect in the US, offshore engineers using Cisco VPN do not see this with the same apps running on the simulator. Sorry I had to obfuscate some info, but I think you will understand.

This all seems to be most closely correlated with the macOS 15.6.1 update.

0

Answer 3

DTS Engineer OP

Apple

2d

Recommended

OK.

That fact that you have problems with macOS’s built-in curl means that this is neither:

A simulator issue
Nor a code-level issue

I think you’ll need to work with your VPN and API server admins to work out why this is failing [1]. My focus is on APIs, and you haven’t even got to that point )-:

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

[1] You could also ask about this over in the Apple Support Community, run by Apple Support, and specifically in the Business and Education topic area, where you’re more likely to find folks with relevant experience. However, it’s possible that they won’t be able to help either, because this seems to be very tightly bound to your specific network setup.

0