Dynamic DNS service issue with CG-NAT

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sultanoswing

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#147388 17-Jun-2014 23:37

Upon switching to BigPipe a couple of days ago (flawlessly easy process, by the way - and I get to keep my current VOIP provider & phone number) I couldn't access my personal webserver, which relies on a dynamic DNS provider (afraid.org).

To help anyone else out with a similar issue i.e. prevent you from tearing your hair out unnecessarily, the problem is with BigPipe's CGN (Carrier grade NAT). As I understand it BigPipe's CGN internally reassigns IP addresses to its network users. In my case, this prevented the dynamic DNS service from correctly being able to access my webserver.

The solution is to request a public IP from Bigpipe - which they very speedily & helpfully provided & all is now working as it should. Roll on IPv6! :)

hio77

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#1068057 18-Jun-2014 00:26

unfortunately, the catch of CGNat is exactly this. you cant have publicly facing services, regardless of using a dynamic dns service or not.

clearly, you required a public ip, and now that bigpipe supplied one, its happy times again :)

sadly, ipv6 wont do much to help this iver, since you need v6 at both ends, unless your translating it midway or tunnelling.

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sbiddle

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#1068083 18-Jun-2014 06:21

sultanoswing:

To help anyone else out with a similar issue i.e. prevent you from tearing your hair out unnecessarily, the problem is with BigPipe's CGN (Carrier grade NAT). As I understand it BigPipe's CGN internally reassigns IP addresses to its network users. In my case, this prevented the dynamic DNS service from correctly being able to access my webserver.

The solution is to request a public IP from Bigpipe - which they very speedily & helpfully provided & all is now working as it should. Roll on IPv6! :)

Not entirely correct.

CG-NAT allows BigPipe to share a single IPV4 public IP with multiple customers, just like your router at home does when it hands out local IP addresses and performs NAT.

IPV6 also isn't necessarily a solution for your problem.

sultanoswing

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#1068750 18-Jun-2014 18:20

Nicely and succinctly, put sbiddle, in terms of what CGN does :)

And yes, I realise IPv6 is a different kettle of fish, but once implemented there will be less need for fudges like CGN (although I also recognise there are actually benefits to it as well).