# IPv4 / IPv6 issue with apt\_repository **URL:** \ **Category:** Ansible Project\ **Tags:** aws\ **Created:** [January 12, 2023, 3:15pm UTC](https://forum.ansible.com/t/ipv4-ipv6-issue-with-apt-repository/37548 "2023-01-12T15:15:59Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Eli\_Taft](https://avatars.discourse-cdn.com/v4/letter/e/e47774/32.png) [@Eli\_Taft](https://forum.ansible.com/u/Eli_Taft)\ **Post date:** [January 12, 2023, 3:15pm UTC](https://forum.ansible.com/t/ipv4-ipv6-issue-with-apt-repository/37548/1 "2023-01-12T15:15:59Z")
Hi everyone, I have two Debian servers on EC2 instances in AWS. I’m using ansible to deploy to them. As far as I can tell they are configured the same (someone else set them up, but I’ve been trying to compare things in AWS console and also on the servers themselves). I am likely wrong about this, just can’t find where the configuration is different. The issue I’m having is that deploying to one server takes forever, and deploying to the other server is really quick. The hang up is happening within apt\_repository. One server is attempting to connect using IPv6 first, and only when all of those time out does it try and succeed to download using an IPv4 address. The other server doesn’t do this… it just using IPv4 and downloads instantaneously. I cannot figure out why these servers are handling the apt\_repository module differently. Is there a some undocumented flag that I could pass to this module to force it to only use IPv4? Like when using wget, how you can pass --prefer-family=IPv4? I’ve looked through the Python code for this module and there doesn’t seem to be an option for that. It just calls fetch\_url. I suppose one thing I could do would be to pass the IPv4 address directly to apt\_repository, but then if that changes I’ll have to manually update again. I’d prefer DNS resolution to be working. Just not sure why it’s not. Both of these servers are using the same network / vpc settings too. Just thought I’d put this out there in case anyone has some bright idea that I’m clearly not seeing. Thanks for your time. Sincerely, Eli ---
**Author:** ![Antony\_Stone](https://avatars.discourse-cdn.com/v4/letter/a/4491bb/32.png) [@Antony\_Stone](https://forum.ansible.com/u/Antony_Stone)\ **Post date:** [January 12, 2023, 3:27pm UTC](https://forum.ansible.com/t/ipv4-ipv6-issue-with-apt-repository/37548/2 "2023-01-12T15:27:54Z")
The first thing I would test is whether both servers can resolve a hostname which has both IPv4 and IPv6 addresses, and whether they can both connect to each address. My suspicion is that one is (mis?)configured with an IPv6 address, and therfore tries to use IPv6, which then fails, and the other server doesn't even have an IPv6 address (or route?) and therefore just goes for IPv4 immediately. For example, this is what I get on one of my (not AWS) machines: $ ping4 -n google.com PING google.com (172.217.16.206) 56(84) bytes of data. 64 bytes from 172.217.16.206: icmp\_seq=1 ttl=57 time=10.2 ms 64 bytes from 172.217.16.206: icmp\_seq=2 ttl=57 time=10.3 ms 64 bytes from 172.217.16.206: icmp\_seq=3 ttl=57 time=10.2 ms $ ping6 -n google.com PING google.com(2a00:1450:4001:806::200e) 56 data bytes 64 bytes from 2a00:1450:4001:806::200e: icmp\_seq=1 ttl=57 time=10.3 ms 64 bytes from 2a00:1450:4001:806::200e: icmp\_seq=2 ttl=57 time=10.3 ms 64 bytes from 2a00:1450:4001:806::200e: icmp\_seq=3 ttl=57 time=10.3 ms Antony. ---
**Author:** ![dnmvisser](https://avatars.discourse-cdn.com/v4/letter/d/8e8cbc/32.png) [@dnmvisser](https://forum.ansible.com/u/dnmvisser)\ **Post date:** [January 12, 2023, 4:12pm UTC](https://forum.ansible.com/t/ipv4-ipv6-issue-with-apt-repository/37548/3 "2023-01-12T16:12:45Z")
Yes, this is definitely not something specific to ansible. I would aim to have both instances being properly dualstack, but I'm an IPv6 evangelist 😛 Apart from what Antony said, it could also be that the instance has somehow gotten an IPv6 address assigned, which makes the OS think it's got dualstack connectivity, but then the required network configuration further up is not there/working. For example there might not be an IPv6 egress internet gateway, or a security group is missing some IPv6 prefix. DIck