Fixed Public IP Address - Gateway

[Shaunzyforest]

Hello

A while back we changed out our business hub for a Ubiquiti Dream Machine.

We had a fixed Ip but have realised since switching to the DM we dont have the fixed IP working anymore.

From what I have read we can enter our fixed IP into the DM but it is asking for a Gateway address.

Is there a way to find this with out going back to the old Hub? Or do we even need to specify it?

Many thanks 

Shaun

[AlanM1]

Hi Shaun 👋

If you had a fixed/static IP on your BT Business service, the gateway address is always part of the IP block BT assigned to you. It won’t show up automatically on the Ubiquiti Dream Machine, so you do need to enter it manually — but you don’t need to reconnect your old hub to find it.

✅ How to find your BT Business fixed IP & gateway

BT publishes all static IP information (including how to identify your gateway) here:
🔗 BT Business – IP Address Help
https://business.bt.com/help/home/broadband-and-internet/ip-addresses/

🔍 Quick explanation

• If BT gave you a single static IP, the gateway is usually the router’s WAN IP provided by BT over PPPoE — meaning you may not need to manually specify it unless the UDM requires it.
• If BT gave you a block of static IPs (e.g., /29 or /30), then:
  • The first address in the block = Network
  • The last address = Broadcast
  • The second address is normally the Gateway
  • The usable IPs are the ones in between

(Example: For 213.xxx.xxx.50/29, the gateway would be .51)

If you're still unsure

Your fixed IP block details will be in your BT order confirmation email or Control Centre.
If you can’t locate it, BT will provide the gateway if you contact them via the Business support page here:  

https://business.bt.com/support/

[Shaunzyforest]

Many thanks for the response.

I have followed the links and still cant find the gateway info. I also Logged into out account but I presume because the hub isnt connected I didnt have access to any advanced information.

I have the welcome email which shows the IP address and subnet mask but no mention of Gateway. Is that because it's not required do you think? We only have a single ip.

Im asking questions as its in a broadcast environment and I'm trying to make sure everything is in order before making the change.

Best 

Shaun

[AlanM1]

Hi Shaun 👋

Thanks for coming back.

If you’ve got a single static IP, it’s normal that the gateway isn’t shown in your welcome email — because in most single‑IP setups, you don’t manually specify a gateway at all. The BT network provides this automatically through PPPoE, so the Ubiquiti Dream Machine won’t normally need you to enter one.

✅ Why the gateway may not appear

For single static IP services, BT typically only assigns:

• 1 static IP address, and
• a subnet mask

The gateway isn’t listed because it’s handled automatically, not manually configured like it is with multi‑IP ranges.

This lines up with what you’re seeing.

🔍 Still want to double‑check your exact setup?

BT can confirm your static IP setup and whether your service requires a manually‑entered gateway.

You can contact BT Business directly here:
🔗 BT Business – Contact Support
https://business.bt.com/support/

They’ll be able to confirm the specific gateway behaviour for your exact circuit, especially important in a broadcast/production environment where downtime matters.

You’re absolutely doing the right thing by checking before making changes — especially on a live broadcast setup. Based on what you’ve described, it sounds like your service is one where the gateway simply isn’t required manually.