IP address confusion

I've been a Giganet customer for almost two years now and in all that time my external IP address never changed and was in the 206.245.x.x range. A couple of days ago this switched to an address in the 188.74.x.x range and this seems to have co-incided with speedtests now showing my ISP as Allpoints Fibre rather than Giganet.

What is confusing me is that the WAN IP address as reported by my router is in the 100.64.x.x range. Now I thought that the WAN IP and the external IP address were one and the same so why would my router be reporting one thing and sites like https://www.whatismyip.com/ reporting something entirely different?

I use a Dynamic DNS Name from noip.com and this is confusing it because it is still resolving the dynamic host name to the old 206.245.x.x. adddress so I'm at a bit of a loss here.

Regards,
Steve

If your router WAN address is different than what whatismyip.com shows (assuming you're not using a VPN) then I am guessing your provider is using CGNAT which means your public IP address is shared by many and not exclusive to you.

The 100.64.x.x address range is reserved for CGNAT, so if you are seeing that then you are stuck with CGNAT, If it where me I would want out of my contract at that point because it is a material change that you didn't agree to.

If it where me I would want out of my contract at that point because it is a material change that you didn't agree to.

That is assuming there is a viable alternative provider

In reply to a post by ian72:

If it where me I would want out of my contract at that point because it is a material change that you didn't agree to.

That is assuming there is a viable alternative provider

Is this something more common on alt nets?

I'm on an Openreach connection, not an altnet. Openreach is the only option for fibre here.

Looks like Giganet now charge £3/mo for a static IPv4 address:
https://www.giganet.uk/faq/can-i-have-a-static-ip-ad...

This is not uncommon for altnets (and, increasingly, all ISPs) due to the general shortage of available IPv4 address space and the fact that most home broadband users won't notice the difference. I suspect that your area been moved, wholesale, to a cgnat configuration, hence the 100.x.x.x address on your WAN connection - effectively you are now double-NATed through a second layer so that they can share a single public IPv4 address across several (perhaps many) broadband customers.

I would speak to them about this as it's clearly a change from what you had before and you may be able to get them to reinstate it for free. But, worst case, you can get it back for £3/mo (which actually isn't too bad - YouFibre want £5/mo for the same thing!)

FYI, if you used any port-forwarded services from your WAN interface, these cannot be made to work as long as you have a CGNAT connection as while you can port-forward from the 100.x.x.x address, you have no control over the actual public NAT, which will be far more dynamic anyway.

If you have the option to switch ISPs, then you might find another that will do this for free, but they are increasingly rare nowadays. Several of the more expensive "boutique" providers will certainly do it, but you'll pay a premium for the privilege. Vodafone used to provide a static IPv4 upon request, but don't know if they still do. Also, they have the worst customer service of any company I can remember dealing with, so you switch to them at your peril!

Edited by daern (Thu 01-Aug-24 11:27:11)

In reply to a post by sjr:

I'm on an Openreach connection, not an altnet. Openreach is the only option for fibre here.

Oh right, sorry I Googled Giganet and they cannot provide me with FTTP at my address and I currently have BT FTTP, this led me to an incorrect assumption.

Thats naughty about the IP.

Giganet was allegedly going to open up their network to wholesale in 2023 so presumably, there are alternative ISPs.

The Giganet checker tells me I can't have their service either and I've been a customer for nearly two years! Whether that;s because they don't want new customers on Openreach or the checker isn't working correctly due to all the internal stuff going on at Giganet I don't know.