Plug in and it just works
A new laptop joins the college Wi-Fi. Nobody types an address. Nobody types a server name. Seconds later, the laptop opens the college website.
Two small services made that happen. One gave the laptop an address. The other turned a name into a number.
Key words
| Word | What it means |
|---|---|
| Network | computers and devices joined together so they can share data |
| Client-server network | a network where client devices ask a central server for services |
| Protocol | a set of rules that devices follow to talk to each other |
| IP address | the number that identifies a device on a network |
| DHCP | a service that gives a device an IP address and other settings automatically |
| Lease | the time a device may keep the address it was given |
| Router | a device that passes data between networks |
| DNS | a service that turns a name, such as files.lab, into an IP address |
| Hostname | the name of a device or server, such as printer.lab |
| Reservation | a rule that always gives the same address to the same device |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can explain what DHCP and DNS do. I can set both up on a small server and test them.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
DHCP: an address without typing
DHCP hands out addresses. A new device shouts to the whole network: "Is there a DHCP server?"
The server picks a free address from its pool and offers it. The device accepts. The server confirms.
The address comes with a lease, for example 12 hours. The reply also names the router and the DNS server.
DNS: names to numbers
DNS works like a phone book. You ask for a hostname. It answers with the IP address.
People remember files.lab. Computers need a number. The DHCP reply tells each client where the DNS server is, so the two services work together.
Check
Have a go
Check
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.