This topic

Using a Third-Party Router Behind BT Smart Hub 2 to Create Guest Networks

MuttersSoftly — Wed, 05 Nov 2025 17:35:15 GMT

Hi all,

Adding guest accounts via bridging routers.

I’ve recently switched from VDSL broadband to FTTP. I would buy a new router in a heartbeat if it weren’t for the fact my landline is now using BT Digital Voice which third-party routers don't support, meaning I'm stuck with the Smart Hub 2 for now.

My old ASUS router allowed me to create multiple guest accounts—each with its own SSID and password. For example:

Guest Account 1: For IoT devices like doorbells and nanny cams, which are often vulnerable to hacking.

Guest Account 2: For two Smart TVs.

Guest Account 3: For friends and family.

All guest networks were fully separated from my primary user account for added security.

However, the BT Smart Hub 2 doesn’t even offer a single guest network option. I want to know if I can bridge my old ASUS router behind the Smart Hub 2 to maintain these segmented guest networks and whether that setup would be compromised by the BT Smart Hub 2.

I’m also miffed that I can’t choose my preferred DNS server Quad9. Yes, I have it set on my PC, which should override the router DNS, but I liked that my IoT and other smart devices were forced to use the Quad9 DNS set by my router.

Any advice or experience with this kind of setup would be really appreciated.

Thanks in advance!

Re: Using a Third-Party Router Behind BT Smart Hub 2 to Create Guest Networks

WSH — Wed, 05 Nov 2025 17:49:01 GMT

Try message 5 here:

https://community.bt.com/t5/Home-phone-including-Digital/BT-Digital-upgrade-to-landline-will-third-p...

...and before you say you have an Asus not a Draytek, the technique is generic and should work with any third-party router.

Re: Using a Third-Party Router Behind BT Smart Hub 2 to Create Guest Networks

TimCurtis — Wed, 05 Nov 2025 17:57:01 GMT

@MuttersSoftly

That link given does provide most of what you need for setting up your Asus , I did mine similarly to that but set the SH2 to 192.168.2.1 and used the mask of 255.255.254.0 as I had devices using the 192.168.0.n range but not sure that was really necessary. The other difference was that used a DSL Asus.

Re: Using a Third-Party Router Behind BT Smart Hub 2 to Create Guest Networks

licquorice — Wed, 05 Nov 2025 18:20:22 GMT

The Asus will be the DNS proxy rather than the Smart Hub2 in that configuration.

Re: Using a Third-Party Router Behind BT Smart Hub 2 to Create Guest Networks

WSH — Wed, 05 Nov 2025 18:24:23 GMT

@TimCurtis Yes, I see you said that last time.

Just out of curiosity, why did you pick a mask of 255.255.254.0? That supports 128 subnets of 512 hosts each. Seems a strange choice for a domestic network, even one with multiple subnets?

Re: Using a Third-Party Router Behind BT Smart Hub 2 to Create Guest Networks

MuttersSoftly — Wed, 05 Nov 2025 18:28:20 GMT

"...and before you say you have an Asus not a Draytek, the technique is generic and should work with any third-party router."

Absolutely agree with you on that, WSH.

Re: Using a Third-Party Router Behind BT Smart Hub 2 to Create Guest Networks

TimCurtis — Thu, 06 Nov 2025 11:22:40 GMT

@WSH

I don't know why TBH. Networking is not my strongest area of expertise.

I just changed it back to 255.255.255.0 and couldn't connect to my ISP so put it back and it's fine now.

As I said Networking etc...

Re: Using a Third-Party Router Behind BT Smart Hub 2 to Create Guest Networks

WSH — Fri, 07 Nov 2025 10:28:48 GMT

@TimCurtis Ah, thought you had something really interesting going on there.

The last time I encountered subnetting in class B like that was one time when I techied for a big primary school, for 12 months, between real jobs. They had a thousand workstations. I inherited the gig, but whoever had set it up originally had used 255.255.252.0, (64 subnets of 1024 hosts).

It just struck me as interesting for a domestic setup. End of the day, if it works, it works.