Checking whether two devices are on the same network

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Checking whether two devices are on the same network

Name:
Date:
Class:
A

Quick Questions

Shade in the A or B circle for each question.

1. A subnet mask is 255.255.255.0. Are 192.168.1.5 and 192.168.1.9 on the same network?
A Yes, both start with 192.168.1
B No, the last numbers (5 and 9) are different
2. A subnet mask is 255.255.255.0. Are 192.168.1.5 and 192.168.2.9 on the same network?
A Yes, both start with 192.168
B No, the network parts 192.168.1 and 192.168.2 differ
3. Device A is on 192.168.1.x and Device B is on 192.168.2.x (mask 255.255.255.0). How does data get from A to B?
A It must go via the router
B It goes straight across the switch
4. Which part of 192.168.1.5 is the host part when the mask is 255.255.255.0?
A 5
B 192.168.1
5. Two devices on the same network can have the same host part, such as both using 192.168.1.5.
A True: the network part makes them different
B False: each host part must be unique in one network
B

Match the Pairs

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

Left columnRight column
1192.168.1.5 and 192.168.1.9 with mask 255.255.255.0 AThe host part (the last number) is not what decides the network. The network part is 192.168.1 versus 192.168.2, so they are on different networks.
2192.168.1.9 and 192.168.2.9 with mask 255.255.255.0 BDifferent networks: the network parts differ, so data must go via the router
3Each device on one network needs its own unique host part CSame network: both start with 192.168.1, so they can talk directly
4Two devices with the same address on one network cause a duplicate address problem D192.168.1.5 and 192.168.1.9
5192.168.1.9 and 192.168.2.9 are on the same network because both end in .9 EDifferent host parts do not mean different networks. The network part 192.168.1 is the same, so they are on the same network.
6192.168.1.5 and 192.168.1.9 are on different networks because the last numbers differ F192.168.1.5 and 192.168.1.5
C

Definitions

same network
D

Fill in the Blanks

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

1.
A: 192.168.1.5 B: 192.168.1.9 mask: 255.255.255.0 network part of both: _________
2.
A: 192.168.1.5 B: 192.168.2.9 mask: 255.255.255.0 same network? __, so use the router
3.
A = 192.168.1.5, B = 192.168.1.9 Each host part must be ______ in a network
4.
A = 192.168.1.5, B = 192.168.1.5 Same address twice = _________ address
5.
if netA == netB: send directly else: send via the ______
E

Spot the Error

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

Question 1
A mask = 255.255.255
B A = 192.168.1.5
C B = 192.168.1.9
D A and B: same network
Question 2
A mask = 255.255.255.0
B A = 192.168.1.5
C B = 192.168.2.9
D A and B: same network
E data goes via the router
Question 3
A mask = 255.255.255.0
B A = 192.168.1.5
C network part of A: 192.168.1.5
D host part of A: 5
Question 4
A PC1 = 192.168.1.5
B PC2 = 192.168.1.5
C Problem: different networks
D Fix: give PC2 192.168.1.9
Question 5
A mask = 255.255.255.0
B A = 192.168.1.5
C B = 192.168.1.9
D Host parts 5 and 9 must match
E A and B: same network

Answer Key

Checking whether two devices are on the same network
Section A: Quick Questions
Q1
A — Yes, both start with 192.168.1
Q2
B — No, the network parts 192.168.1 and 192.168.2 differ
Q3
A — It must go via the router
Q4
A — 5
Q5
B — False: each host part must be unique in one network
Section B: Match the Pairs
Q1
192.168.1.5 and 192.168.1.9 with mask 255.255.255.0 → Same network: both start with 192.168.1, so they can talk directly
Q2
192.168.1.9 and 192.168.2.9 with mask 255.255.255.0 → Different networks: the network parts differ, so data must go via the router
Q3
Each device on one network needs its own unique host part → 192.168.1.5 and 192.168.1.9
Q4
Two devices with the same address on one network cause a duplicate address problem → 192.168.1.5 and 192.168.1.5
Q5
192.168.1.9 and 192.168.2.9 are on the same network because both end in .9 → The host part (the last number) is not what decides the network. The network part is 192.168.1 versus 192.168.2, so they are on different networks.
Q6
192.168.1.5 and 192.168.1.9 are on different networks because the last numbers differ → Different host parts do not mean different networks. The network part 192.168.1 is the same, so they are on the same network.
Section C: Definitions
Q1
same network — Two devices are on the same network when their IP addresses have the same network part under the subnet mask. If the network part differs, data must go via the router.
Section D: Fill in the Blanks
Q1
A: 192.168.1.5 B: 192.168.1.9 mask: 255.255.255.0 network part of both: 192.168.1
Q2
A: 192.168.1.5 B: 192.168.2.9 mask: 255.255.255.0 same network? no, so use the router
Q3
A = 192.168.1.5, B = 192.168.1.9 Each host part must be unique in a network
Q4
A = 192.168.1.5, B = 192.168.1.5 Same address twice = duplicate address
Q5
if netA == netB: send directly else: send via the router
Section E: Spot the Error
Q1
A — A subnet mask has four numbers, like an IPv4 address. It should be 255.255.255.0.
Q2
D — With mask 255.255.255.0 the network parts are 192.168.1 and 192.168.2. They differ, so the line should say different networks.
Q3
C — The mask 255.255.255.0 makes the first three numbers the network part. That is 192.168.1. The last number, 5, is the host part.
Q4
C — Both PCs have exactly the same address, so they are on the same network. The problem is a duplicate address, not different networks.
Q5
D — Devices on one network share the network part, but each needs a unique host part. The hosts 5 and 9 are different, which is correct.