Static IP addresses on a BTnet leased line

What BTnet includes

BT's BTnet service schedule lists IP addressing among the standard components of every BTnet service, whichever plan you choose:

• Static assigned IPv4 addresses: fixed public addresses that come with the service as standard
• Static or dynamic routed IP addresses: further addresses routed to your site, as set out in your order

The number of addresses and how they are routed are set in your order, so tell us what you need when you ask for a quote. BT's standard components refer to IPv4; if you need IPv6, ask us and we will confirm what is available for your order rather than assume it.

BT may also provide DNS (the system that turns names into IP addresses) as set out in your order, although BT's terms say it is not responsible for providing DNS to your own customers.

Assigned and routed addresses in plain words

The two terms describe how the addresses reach your network:

Which you need depends on what you run. A business that only needs a fixed address for its firewall and remote access may need very little. A business publishing several services to the internet needs a routed range and a firewall that handles it. On BTnet wires only your own router or firewall uses these addresses directly; on the managed plans BT's equipment hands traffic to your network at its LAN port.

Why static IPs matter

Many broadband services give you an address that can change. On a dedicated line, a fixed address makes a lot of everyday IT simpler:

• Site-to-site VPNs: each office knows exactly where to find the others; see multi-site leased lines
• Remote access: staff and IT providers connect to a known address
• Allow-listing: cloud services, banks, suppliers and software vendors can restrict access to your office's address
• Hosting services: mail relays, web services or applications you run on site need a fixed public address
• CCTV and building systems: remote viewing and management are easier with a fixed address; see a leased line for CCTV
• Voice services: some voice set-ups, including SIP, rely on a known address; see a leased line for VoIP

A fixed address is not a security measure by itself. Anything you expose to the internet needs a properly configured firewall, current patches and strong authentication.

Who owns the addresses

This is the section of BT's terms that matters most when you plan ahead. Except for addresses expressly registered in your name:

• IP addresses and domain names provided with BTnet remain BT's property, or that of BT's suppliers, and cannot be transferred
• Your right to use them ends when the service ends

In practice, if you move premises or end the service, expect your public addresses to change. Keep a list of everywhere your current addresses are used (VPN peers, allow-lists, DNS records, supplier portals) so renumbering is a checklist, not a surprise. If you are planning a move, read moving office with a BTnet leased line and ask us about addressing early.

Domain names through BT

If you register a domain name through BT with the service, BT's terms say you must own or be authorised to use the name, you pay the registration and renewal fees, and BT does not ensure that a requested name is available or approved.

Provider independent resources

Some organisations need addresses that are not tied to one provider: for example, to keep the same addresses through changes or to run their own routing. BT's terms allow Provider Independent Resources (PIR) with BTnet. These include resources such as autonomous system numbers and provider independent IPv4 addresses, registered through the relevant Regional Internet Registry (RIR).

PIR comes with duties under BT's terms:

• Keep your registration details up to date with BT and answer BT's information requests; some of the data is published in the RIR's database
• Pay any registration fees that apply
• Do not assign the resources to anyone else
• Follow the RIR's policies; if you do not, or cannot be contacted, the resources can return to the RIR

PIR is a specialist choice, usually for larger networks with in-house routing skills. If you think you need it, tell us at quote stage.

What to have ready for an IP address plan

• A list of what you run on site that must be reachable from the internet: VPNs, remote access, servers, cameras, phone systems
• Where your current addresses are used: supplier allow-lists, DNS records, VPN peers and cloud service settings
• Who manages your firewall, and whether they want a routed range on their side of the hand-off
• Any plans for more sites or a move, since addresses provided with the service do not travel with you

With that list, sizing the address allocation is straightforward, and your IT team can prepare the firewall and DNS changes before installation day rather than after it.

How Forever Communications helps

Getting addressing right at the start saves rework later. Forever Communications is an Authorised Supplier for BT, and when you ask us for a BTnet quote, we can help you:

• Work out how many public addresses you need and whether a routed range makes sense
• Plan how addresses fit with BTnet wires only, the managed Cisco router or BTnet Meraki
• Prepare the details your IT team needs for installation day
• Plan for address changes if you are moving or replacing a service

Ask us for a quote: pricing depends on your site, speed, plan and options. Contact us and tell us what you need to run.