Got another incident today (see below.) docker pull on a VritualBox VM on Mac works fine without hitch.
Sending build context to Docker daemon 16.9 kB
Step 1 : FROM nginx:1.9
Pulling repository docker.io/library/nginx
Network timed out while trying to connect to https://index.docker.io/v1/repositories/library/nginx/images. You may want to check your internet connection or if you are behind a proxy.
Just re-installed 1.12.0-rc4-beta20 (build: 10404) while troubleshooting something else & I am now seeing this problem. Don’t seem to be able to pull anything.
I got it working with pure default Docker configuration (no manual DNS set to 8.8.8.8, no IP V6 deactivation), by removing Unlocator-related settings from the router (its specific DNS server, and maybe more problematic, static routes that redirected 8.8.8.8 and 8.8.4.4 to the router itself as recommended to get Chromecast working)! I had to reboot the router afterwards and disable/re-enable local network adapters. Strange that Docker is the only application which encountered issues because of this set-up.
But, if I rearrange the list so that the v4 addresses are at the top, it suddenly works.
So it seems that the issues are that a) it’s not falling-back to the second/third/fourth addresses in /etc/resolv.conf, and b) it doesn’t have access to the IPv6 internet.
Can anybody else confirm that making sure the first DNS address is a v4 address fixes the issue?