In a support thread titled “New Install - Docker Not installing,” Timelord reports an issue installing Docker on a fresh Ubuntu 21.04 system using ./discourse-setup. Despite confirming outbound network connectivity via traceroute, the installation fails. Falco suggests testing with curl -vv https://get.docker.com, which reveals repeated “Network is unreachable” errors for IPv6 addresses Timelord. Falco concludes the server likely has broken IPv6 connectivity. Timelord attempts to disable IPv6 to force IPv4, but the issue persists even on IPv4 Timelord. pfaffman notes the problem is unexplained but recommends using Ubuntu LTS (20.04) for longer-term stability. The root cause remains unresolved, with both IPv4 and IPv6 connectivity appearing problematic despite initial network tests suggesting otherwise.
So, a brand new install on Ubuntu 21.04. I have installed Discourse dozens of times without issue, but this one is tripping me up.
After running ./discourse-setup I get the following
To test basic network connectivity, I traceroute over to get.docker.com, and traffic is leaving the server.
ANy thoughts on what could be going on here?
Try curl -vv https://get.docker.com.
Here is the output from that command.
curl -vv https://get.docker.com
* Trying 65.9.149.88:443...
* Trying 2600:9000:20d1:9000:10:a463:3d00:93a1:443...
* Immediate connect fail for 2600:9000:20d1:9000:10:a463:3d00:93a1: Network is u nreachable
* Trying 2600:9000:20d1:4c00:10:a463:3d00:93a1:443...
* Immediate connect fail for 2600:9000:20d1:4c00:10:a463:3d00:93a1: Network is u nreachable
* Trying 2600:9000:20d1:1c00:10:a463:3d00:93a1:443...
* Immediate connect fail for 2600:9000:20d1:1c00:10:a463:3d00:93a1: Network is u nreachable
* Trying 2600:9000:20d1:1000:10:a463:3d00:93a1:443...
* Immediate connect fail for 2600:9000:20d1:1000:10:a463:3d00:93a1: Network is u nreachable
* Trying 2600:9000:20d1:6e00:10:a463:3d00:93a1:443...
* Immediate connect fail for 2600:9000:20d1:6e00:10:a463:3d00:93a1: Network is u nreachable
* Trying 2600:9000:20d1:ae00:10:a463:3d00:93a1:443...
* Immediate connect fail for 2600:9000:20d1:ae00:10:a463:3d00:93a1: Network is u nreachable
* Trying 2600:9000:20d1:0:10:a463:3d00:93a1:443...
* Immediate connect fail for 2600:9000:20d1:0:10:a463:3d00:93a1: Network is unre achable
* Trying 2600:9000:20d1:f600:10:a463:3d00:93a1:443...
* Immediate connect fail for 2600:9000:20d1:f600:10:a463:3d00:93a1: Network is u nreachable
Looks like you have broken IPv6 connectivity on this server.
Yeah, that’s the conclusion I am coming to also. Gonna try disabling IPV6 and force it to use IPV4.
Interesting, it does not work on IPV4 either.
I don’t have an explanation for your problem, but I’d recommend to always use an LTS version (20.04) as it’ll last a lot longer.