Types of IP addressing
Describe different types of IP addressing
In this lesson
- How IPv4 and IPv6 addresses differ
- Public and private IP addresses, and static and dynamic IP addresses
- How network address translation (NAT) lets many private devices share one public address
LearnIPv4 and IPv6
An IP address identifies a device's connection to a network, so that packets can be routed to it.
CheckQuick check
Which is the correct shortened form of fe80:0000:0000:0000:0204:0000:0000:0001?
LearnPublic and private, static and dynamic
CheckPublic or private?
Classify each IPv4 address.
- 192.168.0.14
- 172.20.5.1
- 172.40.5.1
- 10.200.3.9
- 8.8.8.8
- 192.169.1.1
LearnNetwork address translation (NAT)
LabInside a NAT router
Three devices on a home network share one public address. Send requests from different devices, let a server reply, and see what happens to a packet nobody asked for.
Router’s NAT table (public address 203.0.113.5)
Empty: no device has started a connection yet.
Send requests from two different devices, let a server reply, and try a packet from a stranger, to complete this activity. Addresses are examples.
ExamWorked exam answer
Distinguish between a static IP address and a dynamic IP address.
[2]ReviewMistakes examiners see
Private does not mean secret or encrypted. It means the address is used only inside a local network and is not routed on the internet.
Static and public are different ideas. A printer can have a static private address; a home router can have a dynamic public one.
IPv6 is not “IPv4 with more numbers”: the formats are different, and the two protocols are not directly compatible.
When describing NAT, mention the private and public addresses, the NAT table and what happens to the reply.
Exam practiceExam-style questions
5 questions · 11 marks. Answer each one first, then mark it yourself against the markscheme. Your answers are saved in this browser only.
A small hotel has one internet connection with one public IPv4 address. Guests' phones and laptops connect to the hotel Wi-Fi and are given private addresses. The hotel's booking website runs on its own server in the building.
Calculate how many times more addresses IPv6 provides than IPv4. Give your answer as a power of 2.
The hotel's ISP gives the router a dynamic public address that changes every few days. Outline one problem this causes for customers trying to reach the booking website.
Two guests' laptops both send requests from source port 51000 to the same website at the same time. Explain how the router makes sure each reply reaches the right laptop.
A guest starts a game server on their laptop so that friends at home can join. Explain why the friends cannot connect to it.
The hotel's ISP now offers IPv6. Outline why IPv6 reduces the need for NAT.
0 of 5 questions marked. Mark every question to see your total.
Exam-style questions written for Praxis IB in the format of the 2027 specimen papers. They are not IB past-paper questions.