I'm building a IPv6 enabled FTP container based on pure-ftpd and I have the problem that passive mode needs the client to connect on any port in the range of 30000 to 50000 to the server on the container.

Right now I don't have a solution for opening the port range for the container. With IPv4 I managed to do that with iptables and NAT, but for IPv6 the NAT table is empty. I see, that when I publish a port with IPv6, instead of using iptables like on IPv4, docker listens on that port. What kind of magic it does I don't know.

Maybe a solution would be to assign an address to the container, but I couldn't find a way to do that or I didn't see it.

What possible solutions are there, to forward the whole port range to the server in the container?

  • 3
    It's best to build your own bridge to your physical network interface so that containers can use IPv6 addresses directly. They will also get unique IPv4 addresses in this setup, so you may not need port forwarding/NAT anymore (or may need to move it to an upstream router). Aug 1, 2014 at 1:52


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