3 ms·

Not sure about BT (there's still a NAT involved, but maybe the more conventional NAT64 allows the usual hole punching techniques to work?) or Emby (no idea what

Not sure about BT (there's still a NAT involved, but maybe the more conventional NAT64 allows the usual hole punching techniques to work?) or Emby (no idea what that is). I have no idea why SSH port forwarding wouldn't work with DS- Lite or 464XLAT, since from the network infrastructure's perspective it's a pretty conventional server-client connection.

Fnoord 8y ago
Didn't work for me with DS-Lite/CGN because I couldn't port forward since I didn't have authorization for that on my ISP's CGN server. Outward IPv4 worked perfectly fine, but inward did not. If your client speaks IPv4 only (which is rather common; e.g. my smartphone with 4G has this), it won't be able to talk to your IPv6 who has IPv4 behind CGN. What would work is a port forwarding server. A server which accepts IPv4 connection on a certain port and forward it to the server which accepts IPv6. However, this has several advantages: these services are not free (and rightfully so), and the user is relying on a third party.
- azernik 8y ago
  BitTorrent should work fine, because it has mechanisms for punching UDP holes in NATs (by agreeing on a port combination with a coordination server and having each side send a dummy UDP packet to install the mappings). The one caveat is that, for correct determination of the NATted IP address, the coordination server needs to be IPv4-only. Not sure what's going on with SSH forwarding.
  - Fnoord 8y ago
    Won't work if they don't have correct port forwarding enabled (which a lot of BitTorrent clients suffer from). FTP passive also doesn't work IIRC. SSH port forwarding uses TCP. Say you're listening on your IPv6 address. Well, if your client is IPv4 only you won't be able to connect. Unless you use one of those 4 to 6 services I mentioned.
    - azernik 8y ago
      Ah. I thought you meant SSH port forwarding where the client is on IPv6. Yeah, if the service has an IPv6 address only it's not going to be able to accept connections from an IPv4 client.

Fnoord 8y ago

Didn't work for me with DS-Lite/CGN because I couldn't port forward since I didn't have authorization for that on my ISP's CGN server. Outward IPv4 worked perfectly fine, but inward did not. If your client speaks IPv4 only (which is rather common; e.g. my smartphone with 4G has this), it won't be able to talk to your IPv6 who has IPv4 behind CGN. What would work is a port forwarding server. A server which accepts IPv4 connection on a certain port and forward it to the server which accepts IPv6. However, this has several advantages: these services are not free (and rightfully so), and the user is relying on a third party.

azernik 8y ago
BitTorrent should work fine, because it has mechanisms for punching UDP holes in NATs (by agreeing on a port combination with a coordination server and having each side send a dummy UDP packet to install the mappings). The one caveat is that, for correct determination of the NATted IP address, the coordination server needs to be IPv4-only. Not sure what's going on with SSH forwarding.
- Fnoord 8y ago
  Won't work if they don't have correct port forwarding enabled (which a lot of BitTorrent clients suffer from). FTP passive also doesn't work IIRC. SSH port forwarding uses TCP. Say you're listening on your IPv6 address. Well, if your client is IPv4 only you won't be able to connect. Unless you use one of those 4 to 6 services I mentioned.
  - azernik 8y ago
    Ah. I thought you meant SSH port forwarding where the client is on IPv6. Yeah, if the service has an IPv6 address only it's not going to be able to accept connections from an IPv4 client.