In reply to a post by Alucidnation:

AS for CGNAT, im not sure how i could find out? The 'external' ip address changes on each reboot.

Compare the IP shown on a site such as ipchicken.com or ipquail.com with the External IP shown on your router.

In reply to a post by jchamier:

In reply to a post by Alucidnation:

AS for CGNAT, im not sure how i could find out? The 'external' ip address changes on each reboot.

Compare the IP shown on a site such as ipchicken.com or ipquail.com with the External IP shown on your router.

Ok, so both of those websites results matches the WAN IP address on the router.


Is there a website where i can check what DNS servers i am connected to?

Edited by Alucidnation (Mon 16-Sep-24 17:02:04)

Then you aren’t on CGNAT….99% sure.

In reply to a post by jchamier:

Then you aren’t on CGNAT….99% sure.

In theory, if the WAN IP is the same as your public IP you could be on MAP-T, which is what Sky use for sharing the same IP address between 8 users. But the router needs to be using an ISP-assigned block of TCP/UDP ports for NAT, and this normally means you're using the ISP-provided router.

MAP-T isn't technically CGN, because the provider's network is stateless (that is, there is no stonking great NAT box that all the customer traffic goes through; the NAT state is held entirely on the customer routers). But it *is* a form of address sharing.

In reply to a post by candlerb:

MAP-T isn't technically CGN, because the provider's network is stateless (that is, there is no stonking great NAT box that all the customer traffic goes through; the NAT state is held entirely on the customer routers). But it *is* a form of address sharing.

Ugh! Sounds actually worse than CGN as you can't self identify I know that Sky also provide public IPv6, so at least not all is lost.

To be fair to Sky, their systems will automatically opt-you out of MAP-T if they detect you are using any application which won't work with it, and you can manually request an opt-out just by calling them up.

Hence it's completely transparent for the vast majority of users, and doesn't discriminate against people who want their own IP address.

They are extremely open, and gave a very detailed technical presentation at NetUK1. Slide 18 discusses opt-out, and slide 33 lists some third-party routers which are compatible.

Edited by candlerb (Tue 17-Sep-24 15:06:31)

In reply to a post by candlerb:

To be fair to Sky, their systems will automatically opt-you out of MAP-T if they detect you are using any application which won't work with it, and you can manually request an opt-out just by calling them up.

That is good, they must have nearly enough IPv4 then. As an older UK ISP that makes sense. Unlike the newer ISPs and alternate networks whom just couldn't get remotely enough.

They are extremely open, and gave a very detailed technical presentation at NetUK1. Slide 18 discusses opt-out, and slide 33 lists some third-party routers which are compatible.

Very cool, I've seen EE (BT) slides in the past on how they deployed v6 and run legacy v4 over it for mobile connections. (they may be the only UK mobile telco with v6 widely deployed).

I do like that title. IPv4aaS ... brilliant!

Edited by jchamier (Tue 17-Sep-24 15:55:28)

In reply to a post by candlerb:

In reply to a post by jchamier:

Then you aren’t on CGNAT….99% sure.

In theory, if the WAN IP is the same as your public IP you could be on MAP-T, which is what Sky use for sharing the same IP address between 8 users. But the router needs to be using an ISP-assigned block of TCP/UDP ports for NAT, and this normally means you're using the ISP-provided router.

MAP-T isn't technically CGN, because the provider's network is stateless (that is, there is no stonking great NAT box that all the customer traffic goes through; the NAT state is held entirely on the customer routers). But it *is* a form of address sharing.

Interesting, thanks.

Although not sure i completely understand.

I have used my own Netgear router on this connection and that worked ok?