AZ CLI does not work with IPV6

[ThomasShih]

Describe the bug

az login --debug hangs on urllib3.connectionpool: Starting new HTTPS connection (1): login.microsoftonline.com:443 when I'm using ipv6.

Related command

az login --debug
az logout --debug
etc

Errors

No error, just silently hangs

Issue script & Debug output

Same as earlier issue #31221 (comment)

Expected behavior

AZ login does not hang

Environment Summary

azure-cli 2.77.0

core 2.77.0
telemetry 1.1.0

Dependencies:
msal 1.34.0b1
azure-mgmt-resource 23.3.0

Python location '/opt/homebrew/Cellar/azure-cli/2.77.0/libexec/bin/python'
Config directory '/Users/tshih/.azure'
Extensions directory '/Users/tshih/.azure/cliextensions'

Python (Darwin) 3.13.7 (main, Aug 14 2025, 11:12:11) [Clang 17.0.0 (clang-1700.0.13.3)]

Legal docs and information: aka.ms/AzureCliLegal

Your CLI is up-to-date.

Additional context

I had to turn off IPV6 on my access point in order to authenticate. See #31221 (comment)

[yonzhan]

Thank you for opening this issue, we will look into it.

[github-actions]

Here are some similar issues that might help you. Please check if they can solve your problem.

• az login stuck on connecting to login.microsoftonline.com:443 #28548
• az login hangs there forever on WSL #31221

---

Possible solution (Extracted from existing issue, might be incorrect; please verify carefully)

Solution 1:

Disabling IPv6 has resolved the issue for several users. After disabling IPv6, az login worked again. For example, on macOS, you can use the following commands:

networksetup -listallnetworkservices
sudo networksetup -setv6off Wi-Fi

Reference:

• az login stuck on connecting to login.microsoftonline.com:443 #28548 (comment)
• az login stuck on connecting to login.microsoftonline.com:443 #28548 (comment)
• az login stuck on connecting to login.microsoftonline.com:443 #28548 (comment)
• az login stuck on connecting to login.microsoftonline.com:443 #28548 (comment)
• az login stuck on connecting to login.microsoftonline.com:443 #28548 (comment)
• az login stuck on connecting to login.microsoftonline.com:443 #28548 (comment)
• az login stuck on connecting to login.microsoftonline.com:443 #28548 (comment)
• az login hangs there forever on WSL #31221 (comment)

Solution 2:

Changing the DNS server fixed the issue for some users. Options include using Cloudflare (1.1.1.1) or Google (8.8.8.8). You can test this with the following commands:

nslookup login.microsoftonline.com 1.1.1.1 # Cloudflare
nslookup login.microsoftonline.com 8.8.8.8 # Google

Reference:

• az login stuck on connecting to login.microsoftonline.com:443 #28548 (comment)
• az login stuck on connecting to login.microsoftonline.com:443 #28548 (comment)
• az login stuck on connecting to login.microsoftonline.com:443 #28548 (comment)
• az login stuck on connecting to login.microsoftonline.com:443 #28548 (comment)

Solution 3:

If disabling IPv6 entirely is not desirable, you can instruct glibc to prefer IPv4-mapped IPv6 addresses over native IPv6. On Linux, you can modify /etc/gai.conf by uncommenting the following line:

precedence ::ffff:0:0/96  100

Then restart NetworkManager.

Reference:

• az login stuck on connecting to login.microsoftonline.com:443 #28548 (comment)

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[jiasli]

Azure CLI and its underlying Python HTTP requests library fully support IPv6.

It is very likely you will hit the same issue when you access login.microsoftonline.com directly:

python -c "import requests; print(requests.get('https://login.microsoftonline.com/').status_code)"
curl -I https://login.microsoftonline.com/

Please check the network connectivity to login.microsoftonline.com.