Comment 2 for bug 1713094

Wishlist are feature request. These end up in the roadmap for discussion in order to get prioritized.

You can work around this issue by modifying the squid3 template config in:

/usr/lib/python3/dist-packages/provisioningserver/templates/proxy/maas-proxy.conf.template

While this wont survive an upgrade, it will give you the means to work around the issue for now.

That said, I have a question for you? How many IPv6 addresses does the apt mirror or archive have ? The issue i believe you experiencing is [0], which was to fix the number of retries squid3 does. Before, it would just do 10, which meant that if the mirror had 10 ipv6 address, it would never retry on IPv4. The fix was to increase such retries to 25, so if there were to be 10 ipv6 addresses, it would retry ipv4 addresses after ipv6. If this is not working, then the bug could potentially be an issue with squid.

[0]: https://bugs.launchpad.net/ubuntu/+source/squid3/+bug/1547640