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IPv6

eD2K servers and Kad work over IPv4, and so does njMule with them. But many connections today also have IPv6, where no router translates addresses: a client with a public IPv6 address can be reached directly, even when it is firewalled or has a LowID on IPv4. njMule uses IPv6 alongside IPv4 between clients, by itself. There is nothing to set up.

What njMule does with IPv6​

  • Other clients connect to you over IPv6 on your usual TCP port, as they do over IPv4.
  • Your public IPv6 address travels with you: njMule puts it in the hello it sends to other clients, in its Kad source publishes and in the extended source exchange, with the clients that take it. Clients connected to you hear at once when it changes.
  • Their IPv6 address helps you: from the same places njMule learns the IPv6 addresses of other clients, and connects to a firewalled source there directly, with no callback, or when the connection over IPv4 failed.
  • Sources are asked again over UDP at their IPv6 address, so a source that keeps you in its queue is asked for your place without a new connection.
  • Your router's IPv6 firewall is opened to your ports, through UPnP or PCP, when you use automatic forwarding (see IPv6 pinholes).
  • Sources can be added by hand at an IPv6 address, and links may carry them, written with brackets: [2001:db8::1]:4662.

Servers and Kad nodes stay on IPv4. A client that comes over IPv6 counts with the rest of its /64 network for the connection limits, the bans and the checks of corrupt data, as one home holds a whole /64. Secure identification works over IPv6 too.

Your public IPv6 address​

njMule asks the system which address it would send from to reach the IPv6 Internet: only the route is looked up, nothing is sent. It counts only a global address, not a link-local, unique local, 6to4 or Teredo one. It looks again every ten seconds, so it follows the temporary addresses many systems change during the day, and the log says so:

Clients may reach us at the IPv6 address 2001:db8:1234:5678::20
No IPv6 address to be reached at any more

Where you see it​

  • On the Ports card at the top of Network, in the desktop app and in the web interface: IPv6: 2001:db8:1234:5678::20. Without a line, njMule found no public IPv6 address.
  • In the log, as above.
  • In the publicIpv6 field of the remote-control API's status.

My Info shows the IPv4 address that the server and Kad see.

When IPv6 is not used​

  • Bound to a network interface: the interface njMule keeps to is chosen by its IPv4 address, so while binding is on njMule has no IPv6 address and opens no IPv6 connection, which would leave around the interface.
  • With a proxy: njMule does not tell your public IPv6 address to other clients, which would reach you there around the proxy, and no UDP goes over IPv6, since a proxy's UDP relay carries IPv4 only. See Proxy about what else a proxy changes.
  • With obfuscation required: re-asks over IPv6 go plain, so they are not sent, and those of other clients are not answered.
  • No public IPv6 address: everything works over IPv4 as before.

The IP filter knows IPv4 ranges only: it does not apply to clients that come over IPv6, though bans and connection limits do.