Cambridge O Level Computer Science · Syllabus 2210 · Hardware
Network Interface Card
What is Network Interface Card?
The hardware a computer needs in order to access a network; it provides the wired or wireless connection to the network and is given a MAC address at the point of manufacture.
This definition is part of the Hardware chapter in Cambridge O Level Computer Science.
Common mistakes with Network Interface Card
- 24. “MAC and IP addresses are interchangeable.” Why wrong They identify different things, are given by different parties, and are used for different jobs. A network needs both. Correct model A MAC address identifies the network interface card and is given at manufacture. An IP address identifies a device on a network, is allocated by the network, and is what data is routed to. Exam-safe “A MAC address identifies the network interface card and is assigned at manufacture, whereas an IP address is allocated by the network and allows data to be routed to the device.” Check: which of the two does a router read in order to forward a packet?The destination IP address in the packet's header.
- 25. “A MAC address changes on every network.” Why wrong It describes the IP address. The MAC address belongs to the card, not to the network. Correct model The MAC address is given at the point of manufacture and does not normally change when the device joins a different network. It is the IP address that is allocated afresh by each network. Exam-safe “A MAC address is assigned at manufacture and stays with the network interface card; the device's IP address is allocated by whichever network it joins.” Check: a laptop is used at school and then at home. Which address changes?The IP address. The MAC address stays the same.
Questions students ask about Network Interface Card
What is the difference between a MAC address and an IP address?
A MAC address identifies the network interface card (NIC) and is assigned at manufacture, usually written in hexadecimal; it does not normally change when a device joins a different network. An IP address identifies a device or connection on a particular network and is allocated by that network, either statically or dynamically, so it can change from network to network. A router reads the destination IP address in a packet's header to decide how to forward it.