topic Re: Smart Hub Plus ipv4 configuration in Broadband & Landline

Smart Hub Plus ipv4 configuration

David-A-James — Wed, 18 Jun 2025 17:55:31 GMT

I've just moved to EE's FTTP from Plusnet's FTTC.

I'm trying to configure an (internal) ipv4 addess for the new Smart Hub Pkus to an IP address which is not in one of the private IP address ranges. This doesn't seem to be possible (Error message "The Hub IP address is not a valid privaye IP address") - is setting an IP address outside the private IP address ranges not allowed?

This is the way that I had my Plusnet router configured (this set up goes back many years through many ISPs back as far as Demon Internet).

Re: Smart Hub Plus ipv4 configuration

XRaySpeX — Wed, 18 Jun 2025 17:56:15 GMT

What about it? It's already defaulted to a sensible config.

Re: Smart Hub Plus ipv4 configuration

David-A-James — Wed, 18 Jun 2025 17:58:48 GMT

I have several internal devices with static IP addresses in the other address range - I'd rather not have to change all of them (plus internal DHCP servers).

Is the answer that I can only configure the Smart Hub Plus with an address in one of the private IP ranges (which is what the error message appears to be saying)?

Re: Smart Hub Plus ipv4 configuration

Mustrum — Wed, 18 Jun 2025 18:06:05 GMT

@David-A-James what service have you moved to - speed?

Which PN router were you using?

As with most BT/EE routers these days there is very little you can change from standard, however it may be possible to simply use the PN router simply by changing the Username and password on the PN router.

Re: Smart Hub Plus ipv4 configuration

XRaySpeX — Wed, 18 Jun 2025 18:14:16 GMT

Yes. If you want devices to keep in another DHCP range you would need to set up another subsidiary router with DHCP handing out that range & connected by its WAN i/face.

Or you could change the DHCP range of the SH+ to a Custom range accommodating that other range.

Re: Smart Hub Plus ipv4 configuration

David-A-James — Wed, 18 Jun 2025 18:12:55 GMT

I don't know what the Plusnet router is, but I can't keep using that as I need to retirn it to PlusNet.

Re: Smart Hub Plus ipv4 configuration

David-A-James — Wed, 18 Jun 2025 18:56:02 GMT

The Smart Hub Plus (SH32B according to the label on the bottom of it) won't allow me to set the "Server address range" in the DHCP Server settings to adresses outside the private IP address ranges - you can set the server address range to "Custom", and type in start and end addresses, but when trying to save the settings, the error messages are "The Hub address is not a valid private IP address" (even though I have left that as 192.168.1.254), "The DHCP start IP address is not valid" and "The DHCP end IP address is not valid".

However, if I first disable the DHCP server on the Smart Hub Plus, and reboot the Smart Hub Plus, I can then set the hub's (internal) IPv4 address to the address I want (and that has been retained after a reboot of the hub).

So I think I am now where I wanted to be - the Hub now has the internal IP address that the PlusNet hub used to have, and the DHCP service is now only on my local DHCP servers.

Next step is to configure all the port forwarding that I had previously ...

Re: Smart Hub Plus ipv4 configuration

XRaySpeX — Wed, 18 Jun 2025 19:02:02 GMT

@David-A-James wrote:

even though I have left that as 192.168.1.254.

That is what is preventing you setting a Custom DHCP range. You have to 1st set the router's Gateway IP to fit in with the range you want. Otherwise the Custom range you set will not fit in with router's Gateway IP. Hence those 2 invalid msgs.

Re: Smart Hub Plus ipv4 configuration

David-A-James — Wed, 18 Jun 2025 19:55:07 GMT

If I try to set the hub's IPv4 address and set the custom DHCP IP range at the same time, then I get the three errors I have posted above.

It may be that the sequence: turn off DHCP, reboot, set hub's IPv4 address, reboot, turn on DHCP, set custom start and end of DhCP range, and reboot again, might work - I've not tried that.

But attempting to set a non-private IPv4 address for the hub and matching DHCP start and end addresses in the same step does NOT work.

Re: Smart Hub Plus ipv4 configuration

bobpullen — Wed, 18 Jun 2025 20:33:11 GMT

What exactly do you mean by 'non-private IPv4 address'!? The LAN interface of your Plusnet/EE hub should never be assigned a public IP address. Perhaps you can share what IP addresses/ranges you're actually trying to configure and why? If you have your own DHCP server then why are you trying to also configure DHCP on the hub?

Re: Smart Hub Plus ipv4 configuration

David-A-James — Wed, 18 Jun 2025 20:49:21 GMT

By "non-private IPv4 address" I mean an address that isn't in the private IP address ranges (that is (per RFC1918) 10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, and 192.168.0.0 to 192.168.255.255).

For historical reasons, my internal network is running on a class C network that was assigned to me many years ago (and taken back during one of the times when there was a panic about exhaustion of the IPv4 address range).

You say "The LAN interface of your Plusnet/EE hub should never be assigned a public IP address" and, yes, I am aware that one should not do this, but I'm too lazy to change it (and I don't like changing things that aren't broken).

In practice, it doesn't cause any issues as it does not get out on to the Internet and I don't need to access any hosts that are on the Internet in that class C network.

I don't now want or need to configure DHCP on the hub as I have (as you say) a DHCP server on my local network (and that integrates with the DNS server on my local network}.

So, as I said in my reply of 07:56 PM, I believe I now have a working solution.

Re: Smart Hub Plus ipv4 configuration

bobpullen — Wed, 18 Jun 2025 21:04:06 GMT

@David-A-James wrote:
You say "The LAN interface of your Plusnet/EE hub should never be assigned a public IP address" and, yes, I am aware that one should not do this, but I'm too lazy to change it (and I don't like changing things that aren't broken).

How curious. I have to say that mine and your definitions of 'broken' differ 😉

I wasn't expecting you to be referring to non-private IP's in the literal sense!

Glad to hear you've arrived at a solution that works for you however, to address your original question: -

... is setting an IP address outside the private IP address ranges not allowed?

If it is then I'd warrant a guess that it's entirely unintended as the consumer BT/EE hubs are not designed to support No-NAT/routed public IP assignments.

I'm honestly surprised the Plusnet Hub allowed you to do this.

Re: Smart Hub Plus ipv4 configuration

David-A-James — Wed, 18 Jun 2025 23:00:28 GMT

I can't find a way to quote bobpullen's reply, so ...

In this case, my definition of "broken" is "doesn't work". The setiup I have works now, and has worked for many years with several different ISPs (and on FTTC, ADSL-2, probably ADSL and quite possibly dial-up before that).

I've not said anything about no-NAT/routed public IP - for the avoidance of doubt, the Smart Hub Plus will be NATting my connections and the non-private IP addresses will not be getting out to the Internet.

If I were starting from scratch now (or in recent years, for some value of recent that isn't particularly recent) I'd not be using this set-up, but to convert my local DHCP server, my local DNS server, and the static IP addresses on all of my devices that have static IP addresses (and they have them for good reasons) is a reasonable amount of work, that it would be very easy to make errors whilst doing, and that doesn't get me any advantages.

At the moment, there don't appear to be any DNS entries for the particular class C block I am using, so even the possible problem of there being hosts out there that I'd not be able to access because they have addresses in the class C block I am using doesn't (fortunately and by pure chance) currently apply.

Reddit has a somewhat interesting (2 year old) thread on this at https://www.reddit.com/r/PFSENSE/comments/18h43st/do_i_need_to_use_rfc1918_address_spaces_for_my/

Re: Smart Hub Plus ipv4 configuration

WillKirk — Wed, 18 Jun 2025 23:58:11 GMT

So in summary the OP is doing it wrong, knows he is doing it wrong, doesn’t want to stop doing it wrong and wants the new standard router provided to also allow him to do it wrong so he doesn’t have to stop doing it wrong.

The ‘right way’ you obviously know and are very knowledgeable about so I wouldn’t try to convince you otherwise, but the answer is: no. The private IP address ranges are used to allow standardisation behind the NAT so as to not potentially route traffic out onto a wider area network. So the router is set to use private IPs, not public ones in that sense.

Your intention does not seem to be to deliberately use public IPs to interface with the internet and instead do intend to use the NAT… so, as stated above. In relation to how LANs work in this scenario, you’re trying to work against it not with it… up to you.

Re: Smart Hub Plus ipv4 configuration

David-A-James — Thu, 26 Jun 2025 02:58:29 GMT

I think I admit defeat ...

I can (as I have said in a post above) assign the IPv4 addtress I want to the EE Smart Hub Plus's internal (LAN) interface(s), I find that having done that I don't appear to be able to get port forwarding to work.

I've now put the Smart Hub Plus back to default settings (in the 192.168.1.0/8 network, and made some temporary changes to IPv4 addresses on the devices in the internal networkso that they can see the hub and it can see them), and now port forwarding appears to work.

So I guess I'm going to have to bite the bullet and change all my internal IP addresses ...