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.

Everything I can see suggests Giganet don't use OpenReach. Are you sure it isn't a CityFibre connection? If you look on OpenReach only ISPs like EE do they offer you a FTTP service?

See there was this post in february where someone was being transferred by Giganet to Home Telecom - has your service been moved which could explain the change in IP provision?

Thanks for the explanation. Would now being behind CGNAT break using a Dynamic DNS host name from noip,com? I've rebooted the router a few times and the portal at noip.com doesn't show the IP associated witht he host name being updated. And if I were to move to a different ISP is there any way to tell if they use CGNAT or not?

It is 100% certain an Openreach connection as that;s the only option here. Online checkers for Zen, EE etc all show FTTP availablity. I do remember that post about Giganet transferring customers to Home Telecom but I thought that was FTTC customers as up until a couple of days ago nothing had changed on the service provision. Billing was moved to Cuckoo Fibre a month or two ago but no change in service until now.

In reply to a post by sjr:

Thanks for the explanation. Would now being behind CGNAT break using a Dynamic DNS host name from noip,com? I've rebooted the router a few times and the portal at noip.com doesn't show the IP associated witht he host name being updated. And if I were to move to a different ISP is there any way to tell if they use CGNAT or not?

Yes, it would break your DDNS as: 1) the IP address you are seen from on the internet will change far more frequently so it may frequently be wrong and; 2) regardless of this, you can never connect back to your home network via this hostname / IP address because of the dual-NAT. The IP address you are seen as is not your router's address, but the address given out by your ISPs CGNAT gateway.

Most ISPs will advertise whether or not they use cgnat, but otherwise it's a case of Googling for them, or you may be able to find a list on here somewhere. If they offer an additional charge for a static IPv4 address, then it's quite likely they use cgnat for all customers not paying this extra charge.

In that case I agree with the previous poster who said to use it as a reason to leave the contract and move to someone else - there are plenty of options out there. If CGNAT is not viable for you and Giganet won't move you back to a dynamic or static IP then tell them it is a material change to your contract and you want out (that is assuming you are in contract).

In reply to a post by ian72:

In that case I agree with the previous poster who said to use it as a reason to leave the contract and move to someone else - there are plenty of options out there. If CGNAT is not viable for you and Giganet won't move you back to a dynamic or static IP then tell them it is a material change to your contract and you want out (that is assuming you are in contract).

Sadly I would be surprised if there has been a material change to the contract unless the type of IP is specified in the contract. Normally the contract gives them the right to do what they want.

Also see daern's answer but for others reminder that DDNS only updates a DNS entry for the apparent public IP your traffic is coming from, and does not of itself open any port forwarding or firewall rules.

In the case of CGNAT, there are updated protocols for customer routers to request that that the upstream CGNAT device forward a port (or range of ports) but not easy to find out unless the ISP provides good support or documentation about this.


There is a less common variation where the ISP assigns a static range of ports to each subscriber
(e.g 100 ports each for 480 subs per CGNAT engine IP would be 48000 with about ¼ of the ports left dynamic).
Terrible example but you get the idea how rough it is if too many customers behind a single IP.

Edited by prlzx (Thu 01-Aug-24 13:30:37)

In reply to a post by prlzx:

There is a less common variation where the ISP assigns a static range of ports to each subscriber
(e.g 100 ports each for 480 subs per CGNAT engine IP would be 48000 with about ¼ of the ports left dynamic).
Terrible example but you get the idea how rough it is if too many customers behind a single IP.

But of course you still have to worry that noone else using that IP misbehaves and gets the IP address blacklisted anywhere...

CGNAT. Ngggg :-/

Post deleted by naylor2006

I think i'd pay the 3 quid to be honest.....sure if you can get out of your contract due to a material change like some other folks have suggested then maybe do that....but if your IP is really important you can pay for a static which is better than the dynamic one you had before.

I deleted me post before because I accidentally replied to myself.

In reply to a post by ian72:

Everything I can see suggests Giganet don't use OpenReach. Are you sure it isn't a CityFibre connection? If you look on OpenReach only ISPs like EE do they offer you a FTTP service?

See there was this post in february where someone was being transferred by Giganet to Home Telecom - has your service been moved which could explain the change in IP provision?

Giganet used to offer a service via Openreach, but stopped doing so earlier this year presumably as a result of the consolidation of Fern Trading's various entities - Giganet, Jurassic Fibre, Swish Fibre, AllPoints Fibre. Cuckoo is to be the customer-facing brand of their own ISP (though I think the desire is to offer wholesale services on their AllPoints Fibre networks).

See these news articles...
* www.ispreview.co.uk/index.php/2023/02/fern-consolidates-uk-isps-jurassic-fibre-swish-fibre-giganet-and-allpoints-fibre.html
* www.ispreview.co.uk/index.php/2024/05/giganets-uk-broadband-isp-customers-start-migrating-to-cuckoo.html

In reply to a post by sjr:

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.

Giganet/Cuckoo are not taking on new Openreach connected customers.

It's a possibility they might flog said Openreach FTTP customers off to another provider, as they have done with their Openreach FTTC customers.

In reply to a post by prlzx:

In the case of CGNAT, there are updated protocols for customer routers to request that that the upstream CGNAT device forward a port (or range of ports) but not easy to find out unless the ISP provides good support or documentation about this.

I was just reading the RFCs for this (6888 for CGNAT and 6887 for PCP)

PCP dates back to 2013, and should be backwards compatible with NAT-PMP. The RFC for CGNAT says implementations MUST also implement PCP. But of course, there's nothing to say ISPs cannot choose to disable or block it. I wonder if anyone has tried sending NAT-PMP requests upstream to see if they work.

Also considering common ports (http/https). I really don't think there's a reason (if implemented well) this wouldn't be possible for everyone that wanted it. Considering how many people want to, and know how to run a web server on their home network and from that subset how many would already be with an ISP with a static IP. The remainder could likely be assigned an IP address without an assignment on those ports already.

I suspect though, that even if NAT-PMP/PCP are supported and allow for forwarding. Dynamic assignment of IPs based on the need for special ports is extremely unlikely.

I've spoken to them and had a bit of a moan about it. They've said that if they can't come up with a solution they may waive the £3 monthly fee for a static IP. Let's see what happens.

In reply to a post by sjr:

I've spoken to them and had a bit of a moan about it. They've said that if they can't come up with a solution they may waive the £3 monthly fee for a static IP. Let's see what happens.

Sounds promising!

Yes I thought not taking on new Openreach customers was the most likely explanation. If they do flog us off, it will be a real shame as in the nearly 2 years as a customer the service has been great. £32 a month for an excellent 150Mb service and not with one of the big boys, where else can I get that?

In reply to a post by sjr:

Yes I thought not taking on new Openreach customers was the most likely explanation. If they do flog us off, it will be a real shame as in the nearly 2 years as a customer the service has been great. £32 a month for an excellent 150Mb service and not with one of the big boys, where else can I get that?

The obvious possible for 12 months would be Aquiss. Small provider. Static IPv4 and IPv6 addressing as standard. £21 for first 6 months then £42 for the rest of the contract averaging at £31.50 per month. No price rises in contract. Not sure what happens at the end of the 12 months and whether you can get any discounts as that is when it would start costing you extra.

In reply to a post by ian72:

In reply to a post by sjr:

Yes I thought not taking on new Openreach customers was the most likely explanation. If they do flog us off, it will be a real shame as in the nearly 2 years as a customer the service has been great. £32 a month for an excellent 150Mb service and not with one of the big boys, where else can I get that?

The obvious possible for 12 months would be Aquiss. Small provider. Static IPv4 and IPv6 addressing as standard. £21 for first 6 months then £42 for the rest of the contract averaging at £31.50 per month. No price rises in contract. Not sure what happens at the end of the 12 months and whether you can get any discounts as that is when it would start costing you extra.

I've a vague notion that Aquiss will only offer another discount for those customers who have been with them for something like 3 or 4 years.

Another option, though with one of the 'big boys', would be NOW Full Fibre 100 ('powered by Sky') - currently £26 a month but down to £24 if you go through Uswitch or another affiliate link (e.g. ThinkBroadband's affiliate link on this page). 24 month contract, with a potential price rise during the contract but it's not set at a predetermined level - meaning you can leave penalty-free if desired.

Alas they said they would not cover the additional cost of a static IP as that would be my choice and it isn't a necessity so I've asked them to change to a static IP and suck up the extra £3 . My contract expires at the end of October so only a couple more months payments to go and I'll review my options then.

Edited by sjr (Thu 01-Aug-24 16:35:33)

I would seriously consider PlusNet, one of £5 charge for a static IP and it comes with a DNS entry of the form <username>.plus.com

That's not a bad shout if it is a one-off £5 for a static IP. Looks like they're OK with using my own router and the prices are good. Are they any good now though?

In reply to a post by sjr:

£32 a month for an excellent 150Mb service and not with one of the big boys, where else can I get that?

£29.99 for 1G/1G with YouFibre here. Of course, that's not with Openreach, but it does demonstrate that competition on the street can reduce prices *and* deliver better service! (sadly, another fiver on top for a static IPv4 address / no CGNAT, but it's still a decent price)

Oh, and their support is top notch. Phone 'em up, answer phone in a few seconds, and can answer questions like "Can you reset the cached MAC on my ONT, please?" without responding with stupid questions about "your wifi is not working?" After years with Vodafone, I *really* appreciate this!

I'm with Plusnet on 500/75 FTTP and it's fine, no problems full speed all the time, use own Asus router.

Unless I missed some posts in the thread and looking at your first post - I'm not sure why you want a static IP? You mention your DDNS was not working which was because of CGNAT, and the whole point of DDNS is for dynamic IPs which is nothing to do with CGNAT. Granted with some ISPs you'd need to pay for static just to get a public IP

Plusnet is IPv4 only with a dynamic public IP and I use DDNS just fine.

Edited by adrenalize_ (Thu 01-Aug-24 21:56:48)

I suppose I should hve caveated that by saying on Openreach, no altnets here. Even getting Openreach fibre was a long term community fibre partnership project. The only altnet anywhere near here is Trooli and they do serve the centre of the village but we're about a mile down a country lane from the village centre and I doubt they have plans to run fibre down to us given that Openreach have.

https://forums.thinkbroadband.com/fibre/t/4761603-re...

That post explains why DDNS doesn't work on a CGNAT connection and everything a google search I've looked at says the same. DDNS is probably working fine for you because a google search suggests that Plusnet don't use CGNAT.

The irony of course is that if I get a static IP from Giganet I don't really need DDNS but DDNS won't work without one. Should I move to plusnet I won't need a static IP as DDNS will work all the time they're not using CGNAT.

Edited by sjr (Fri 02-Aug-24 09:11:23)

Lots of good providers out there that don't use CGNAT on the Openreach network, any of them is going to be better than the Giganet CGNAT solution.

I suspect Giganet don't really care if you stay or go as they have already laid out their roadmap which doesn't seem to include the Openreach network. I would suggest leaving once you are out of contract.

In reply to a post by PCJM40:

Lots of good providers out there that don't use CGNAT on the Openreach network, any of them is going to be better than the Giganet CGNAT solution.

Mostly the "older" providers have a range of IPv4 addresses from a long time ago before they ran out globally.

Newer providers (such as altnets, or those that operate over Openreach or CityFibre networks) can't get IPv4, so have no choice but to use CGNAT, but they should ALSO provide a public IPv6, those that don't provide IPv6 are to be avoided.

That's my thinking too. Shame though as I prefer the smaller suppliers and the service has been great up until this. Also, they are significantly cheaper than the likes of IDnet, Zen etc.

Edited by sjr (Fri 02-Aug-24 12:12:52)

Paying the £3 for a static IP is alas not an option. I've just spoken to Giganet again and they're saying they now can't do a static IP on a BTW Openreach connection.

In reply to a post by sjr:

Paying the £3 for a static IP is alas not an option. I've just spoken to Giganet again and they're saying they now can't do a static IP on a BTW Openreach connection.

Well that sucks. Would be an immediate termination due to change in supply and a new ISP for me. Bloody [censored] thing for them to do without warning.

Yup, really sucks so I've signed up for Plusnet today

I've just noticed the same issue coming back from holiday.

CGNAT is annoying - I'd probably pay the £3 if needed -- but if they can't offer it... grrr!

Even more frustrating is:
- my ipv6 prefix has changed. It was a fixed /48, now it's a 56. I can deal with this, but *is it fixed or not*. ?
- my 1st hop latency has gone up by ~3ms. How much of this is the cgnat change? I'm guessing just a smaller part, and that there are bigger network changes made too (location: hove/brighton)

Giganet still offer a good price, and nothing is actually broken for me, but it's annoying. Have emailed them and starting to consider other ISPs.

Any local experience on latency welcome since as we know it is SO variable. Aquiss, perhaps zen come to mind.

I should add that I wasn't impressed by the lack of communication from them. (unless I missed it?)

In reply to a post by planetf1:

I've just noticed the same issue coming back from holiday.

CGNAT is annoying - I'd probably pay the £3 if needed -- but if they can't offer it... grrr!

Even more frustrating is:
- my ipv6 prefix has changed. It was a fixed /48, now it's a 56. I can deal with this, but *is it fixed or not*. ?
- my 1st hop latency has gone up by ~3ms. How much of this is the cgnat change? I'm guessing just a smaller part, and that there are bigger network changes made too (location: hove/brighton)

Giganet still offer a good price, and nothing is actually broken for me, but it's annoying. Have emailed them and starting to consider other ISPs.

Any local experience on latency welcome since as we know it is SO variable. Aquiss, perhaps zen come to mind.

With the switch to CGNAT I didn't notice any effect on latency and speedtests that previously topped out at just under 150Mb were reporting 157Mb or thereabouts so had my dynamic DNS host name stopped working I probably wouldn't have noticed or cared. Nothing was communicated to me prior to the switch so you're not alone in that regard. I doubt emailing them will achieve anything, they're not going to take you off CGNAT and won't offer a static IP so your choices are lump it or go elsewhere. I'm going to Plusnet, by all accounts the service is decent and the price is good (£30 for 300Mb) so twice the speed I was getting at Giganet for a couple of pounds less a month. I'd have preferred to go to an Idnet, Aquiss or Zen but you're not getting any of them for the £32 I was paying Giganet. I'll also get £35 for signing up through topcashback.
Other than to DDNS not working, the account portal at order.giganet.uk isn't updating and for me still shows the old IP address but as offline.

Edited by sjr (Mon 05-Aug-24 13:14:38)

Plusnet went live on Monday. I woke up to green lights on the ONT but red on the router and trying to re-connect with the Plusnet credentials gave a failed to authenticate error. A quick call to Plusnet and they told me that their systems showed that Openreach had done their part of the work but they had failed to notify Plusnet in order for them to activate my account. That was done instantly while on the phone and the lights on the router turned green. But other than that it was a smooth transition and I'm up and running with the DGA4134 router that was supplied by Giganet. Other than changing the credentials in the router, the only change was to disable IPv6 because Plusnet is IPv4 only as far as I can tell. Only two days in to Plusnet but so far it has been good and all my woes with dynamic DNS host names are solved.