I am using docker version 1.7 on centos-6:docker --versionDocker version 1.7.1, build 786b29d/1.7.1The problem is: when somehow the /etc/resolv.conf file contains nameservers with ipv6 addresses, then it cannot resolve or pull some repos from github. when I change name servers to IPv4 addresses only , it works again. Is there any permanent solution to this problem? Do upgrading the docker version will fix it?Or is there any other root cause of this problem?The network settings of docker inspect command:NetworkSettings: {    Bridge: ,    EndpointID: db30701ee55cf8f6b8c9fe42c820434648ed6cca5ca863c60e098f9d4ad825a3,    Gateway: 172.17.42.1,    GlobalIPv6Address: ,    GlobalIPv6PrefixLen: 0,    HairpinMode: false,    IPAddress: 172.17.0.8,    IPPrefixLen: 16,    IPv6Gateway: ,    LinkLocalIPv6Address: ,    LinkLocalIPv6PrefixLen: 0,    MacAddress: 02:42:ac:11:00:08,    NetworkID: db3910e86d7f291d5586c23895a67a1140e638afcdbbf5a6b60e10c9bbb85762,    PortMapping: null,    Ports: {},    SandboxKey: /var/run/docker/netns/4273c53a95b2,    SecondaryIPAddresses: null,    SecondaryIPv6Addresses: null},on the host , ipv6 is fully configured and ping6 command works fine. but inside the container i see ipv6 fields blank. Any reason why there is no ipv6 inside the container?moreover :curl -g 'http://[2400:fc00:854a:aaaa:700d:d110:e593:8d00]'curl: (7) Failed to connect to 2400:fc00:854a:aaaa:700d:d110:e593:8d00: Network is unreachable
Docker container cannot pull github repo , name resolution fails
centos;docker;ipv6
You are not getting any IPv6 routing/working inside the containers because as we have seen it, there is no IPv6 addressing working inside them, but only at the host level.As per the IPv6 user guide - networking - IPv6 with DockerBy default, the Docker server configures the container network for  IPv4 only. You can enable IPv4/IPv6 dualstack support by running the  Docker daemon with the --ipv6 flag. Docker will set up the bridge  docker0 with the IPv6 link-local address fe80::1.By default, containers that are created will only get a link-local  IPv6 address. To assign globally routable IPv6 addresses to your  containers you have to specify an IPv6 subnet to pick the addresses  from. Set the IPv6 subnet via the --fixed-cidr-v6 parameter when  starting Docker daemon:dockerd --ipv6 --fixed-cidr-v6=2001:db8:1::/64  The subnet for Docker  containers should at least have a size of /80. This way an IPv6  address can end with the containers MAC address and you prevent NDP  neighbor cache invalidation issues in the Docker layer.With the --fixed-cidr-v6 parameter set Docker will add a new route to  the routing table. Further IPv6 routing will be enabled