Static IP address
A static IP address is a public internet address that stays the same over time, unlike a dynamic address that your broadband provider can change without notice. For Cyber Essentials it matters when you protect a firewall admin interface with an IP allow list (A4.11) and when the Cyber Essentials Plus assessor scans your addresses.
- Term
- Static IP address
- Also known as
- Fixed IP address, Dynamic IP address
- Category
- Networks and firewalls
- Requirement area
- 1. Firewalls
- Questions
- A4.11
- Reviewed against
- Requirements v3.3
What does the term Static IP address mean in Cyber Essentials?
A static IP address is a public internet address that stays the same over time, unlike a dynamic address that your broadband provider can change without notice.
How does Static IP address apply to Cyber Essentials?
In plain terms
A static address is like having a permanent street address. A dynamic address is like being moved to a different house every so often. Many home and small business broadband packages give you a dynamic address by default. Business lines often offer a static one, sometimes for an extra fee.
What Cyber Essentials asks
The scheme does not require a static address. It becomes useful in two places.
First, the firewall admin interface. If you let your IT supplier change firewall settings over the internet, the requirements say access must have a clear, documented business need and be protected by either MFA or "an IP allow list that limits access to a small range of trusted addresses combined with a properly managed password authentication approach". An allow list only works if the trusted addresses stay the same, so the supplier's side usually needs a static address. This is covered by A4.9 to A4.11.
Second, the external scan for Cyber Essentials Plus. The test specification allows for dynamic addresses: "Where dynamic IP addresses are in use for an Internet connection, the scope may be defined in terms of appropriate DNS entries."
Common mistakes
- An allow list pointing at an old supplier address that has since changed or been reassigned.
- Giving the assessor an address list that is out of date because a dynamic address moved.
See A4.11 and Test 1: the external vulnerability scan. Related: IP address, DNS, admin interface.
Related terms
- IP addressAn IP address is the number that identifies a device or internet connection on a network, so that traffic can be delivered to the right place.
- DNS (Domain Name System)DNS, the Domain Name System, is the internet's address book that turns names people can read, such as example.co.uk, into the number addresses computers use.
- Admin interfaceAn admin interface is the settings page or login a device offers so that someone can manage it, such as your router's web settings page.
- VLAN (virtual local area network)A VLAN, or virtual local area network, is a way of splitting one physical office network into separate networks that cannot talk to each other unless you allow it.
- VPN (virtual private network)A VPN, or virtual private network, is an encrypted link over the public internet that lets a device or office connect to another network as if it were plugged in there.
- WPA2 and WPA3WPA2 and WPA3 are the security settings that scramble Wi-Fi traffic and control who can join a wireless network, with WPA3 being the newer and stronger of the two.
Frequently asked questions
A static IP address is a public internet address that stays the same over time, unlike a dynamic address that your broadband provider can change without notice.
In the 2026 Danzell question set, Static IP address comes up at A4.11. Read those questions against the definition above so your answers use the term the way the assessor will.
Static IP address relates to 1. Firewalls in the NCSC's Cyber Essentials: Requirements for IT Infrastructure v3.3. Read that section for the control your answers must show.
Would you pass the 2026 question set?
Answer 24 yes or no questions, built by the assessors who mark Cyber Essentials, and get a readiness score in about five minutes, with any auto-fail questions you miss flagged first in your results.