Network hardware
Network hardware
- To join a network, a device needs a network interface card.
- Devices are identified by a MAC address and an IP address.
- A router connects different networks together.
Network interface card (NIC)
- A NIC is the hardware that lets a device join a network and send/receive data.
- Each NIC has a built-in MAC address.
Practice
A network interface card (NIC):
The NIC is the hardware that connects a device to a network; each one has a built-in MAC address.
MAC address vs IP address
- A MAC address identifies one physical device. The maker sets it, it does not normally change, and it is written in hexadecimal.
- An IP address identifies a device on a network. It is given by the network and can change.
- So the MAC stays with the device; the IP depends on the network it's using.
Practice
Which is true of a MAC address compared with an IP address?
The MAC stays with the device (set by the maker, written in hex); the IP depends on the network and can change.
Practice
A MAC address is normally written in hexadecimal.
MAC addresses are written in hexadecimal (e.g. AC:DE:48:00:11:22).
Practice
A device's IP address can change depending on the network it is using.
IP addresses are assigned by the network, so the same device can have different IPs on different networks.
Router
- A router connects different networks together — e.g. your home network to the internet.
- It reads the IP address in each packet and forwards it towards the right network.
Practice
A router:
A router joins networks (e.g. home to internet) and forwards each packet using its destination IP.
You've got it
Key idea
- a NIC lets a device join a network and holds its MAC address
- MAC = fixed to the physical device (hex, set by the maker); IP = from the network, can change
- a router connects networks and forwards packets by their IP address