Default gateway

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Quick Questions

Shade in the A or B circle for each question.

1. A laptop wants to reach a website that is not on its own network. Where does it send the data first?

A Straight to the website's server

B To the default gateway

2. Which address is usually used as the default gateway on a home network?

A The laptop's own MAC address

B The router's LAN address, e.g. 192.168.1.1

3. A phone at 192.168.1.20 sends data to a printer at 192.168.1.30 on the same network. Is the default gateway needed?

A No, the destination is on the local network

B Yes, all data must go via the gateway

4. A student's computer has no default gateway set. What happens when they try to open a website?

A The device cannot reach the internet

B The device finds the website another way

5. Which statement about the default gateway is correct?

A It is the exit point from the local network

B It turns domain names into IP addresses

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1Default Gateway: 192.168.1.1		AWith no default gateway set, a device cannot send data outside its own network, so it cannot reach the internet. It could still talk to local devices.
2ipconfig		BA Windows command that shows a device's IP address, subnet mask and default gateway
3The default gateway is usually the router's LAN address, so it sits in the same network as the device		Cdestination not local -> send to gateway
4Data for a destination on another network, such as a website, is sent to the gateway first		DThe gateway is on a different network from the device. A gateway must be a router address on the device's own network, such as 192.168.1.1.
5IP: 192.168.1.25 Gateway: 10.0.0.1		EThe router address this device sends data to when the destination is outside its own network
6Gateway: (blank) - the internet works fine		FIP: 192.168.1.25 Gateway: 192.168.1.1

Definitions

default gateway

Fill in the Blanks

Complete each line of code by filling in the missing parts.

Default _______ . . . . . : 192.168.1.1

IF gateway = NONE THEN internet = _____

IF ___ same_network(dest, my_ip) THEN send_to(gateway)

IF destination is on my network THEN send directly to the destination ____ send to the default gateway

Router LAN address: 192.168.1.1 Default gateway: ___________

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A IP address: 192.168.1.20

B Subnet mask: 255.255.255.0

C Default gateway: 192.168.2.1

Question 2

A IP address: 10.0.0.15

B Subnet mask: 255.255.255.0

C Router LAN address: 10.0.0.1

D Default gateway: 8.8.8.8

Question 3

A destination = 8.8.8.8

B IF destination on my network

C send directly

D ELSE send to DHCP server

Question 4

A IF destination is remote

B discard the packet

C ELSE

D send directly

Question 5

A gateway = web server address

B IF gateway is empty

C no internet access

Answer Key

Default gateway

Section A: Quick Questions

B — To the default gateway

B — The router's LAN address, e.g. 192.168.1.1

A — No, the destination is on the local network

A — The device cannot reach the internet

A — It is the exit point from the local network

Section B: Match the Pairs

Default Gateway: 192.168.1.1 → The router address this device sends data to when the destination is outside its own network

ipconfig → A Windows command that shows a device's IP address, subnet mask and default gateway

The default gateway is usually the router's LAN address, so it sits in the same network as the device → IP: 192.168.1.25 Gateway: 192.168.1.1

Data for a destination on another network, such as a website, is sent to the gateway first → destination not local -> send to gateway

IP: 192.168.1.25 Gateway: 10.0.0.1 → The gateway is on a different network from the device. A gateway must be a router address on the device's own network, such as 192.168.1.1.

Gateway: (blank) - the internet works fine → With no default gateway set, a device cannot send data outside its own network, so it cannot reach the internet. It could still talk to local devices.

Section C: Definitions

default gateway — The router address a device sends data to when the destination is not on its own network. It is usually the router's LAN address. With no gateway set, a device cannot reach the internet.

Section D: Fill in the Blanks

Default Gateway . . . . . : 192.168.1.1

IF gateway = NONE THEN internet = FALSE

IF NOT same_network(dest, my_ip) THEN
  send_to(gateway)

IF destination is on my network THEN
  send directly to the destination
ELSE send to the default gateway

Router LAN address: 192.168.1.1
Default gateway: 192.168.1.1

Section E: Spot the Error

C — The default gateway is the router's LAN address, so it must be on the same network as the device. With mask 255.255.255.0 and IP 192.168.1.20, the gateway should be 192.168.1.1, not 192.168.2.1.

D — The default gateway is usually the router's LAN address (10.0.0.1 here). 8.8.8.8 is a public server on another network, so it is not the gateway.

D — When the destination is not on the device's own network, the data goes to the default gateway (the router). A DHCP server only hands out addresses; it does not forward data.

B — If the destination is outside the local network, the device sends the data to the default gateway so the router can pass it on. It should not discard the packet.

A — The default gateway is the router's LAN address, not the address of a web server. The device sends data to the router, which passes it on.