Jawaban Soal Subnetting:
1. A company has the following addressing scheme requirements:
-currently has 25 subnets
-uses a Class B IP address
-has a maximum of 300 computers on any network segment
-needs to leave the fewest unused addresses in each subnet
What subnet mask is appropriate to use in this company?
a. 255.255.240.0
b. 255.255.248.0
c. 255.255.254.0
d. 255.255.255.0
e. 255.255.255.128
f. 255.255.255.248
· Subnet mask kelas B à 255.255.0.0
· Host à 2n-2 ≥ 300
2n ≥ 302
n ≥ 9
11111111.11111111.11111110.00000000
Subnet mask à 255.255.254.0
· Subnet à 2n ≥ 25
n ≥ 5
11111111.11111111.11111000.00000000
Subnet mask 255.255.248.0
2. Refer to the exhibit. Host A is being manually configured for connectivity to the LAN. Which two addressing scheme combinations are possible configurations that can be applied to the host for connectivity? (Choose two.)
a. Address - 192.168.1.14
Gateway - 192.168.1.33
b. Address - 192.168.1.45
Gateway - 192.168.1.33
c. Address - 192.168.1.32
Gateway - 192.168.1.33
d. Address - 192.168.1.82
Gateway - 192.168.1.65
e. Address - 192.168.1.63
Gateway - 192.168.1.65
f. Address - 192.168.1.70
Gateway - 192.168.1.65
3. A NIC of a computer has been assigned an IP address of 172.31.192.166 with a mask of 255.255.255.248. To which subnet does the IP address belong?
a. 172.31.0.0
b. 172.31.160.0
c. 172.31.192.0
d. 172.31.248.0
e. 172.31.192.160
f. 172.31.192.248
· Subnet terakhir 248 = 29 à 11111111.11111111.11111111.11111000
· 256-248=8
· Range IP kelipatan 8, IP 172.31.192.166 berada pada urutan subnet 172.31.192.160
4. Which subnet masks would be valid for a subnetted Class B address? (Choose two.)
a. 255.0.0.0
b. 255.254.0.0
c. 255.224.0.0
d. 255.255.0.0
e. 255.255.252.0
f. 255.255.255.192
· 255.255.0.0 à 2 oktet pertama full (kelas B)
255.255.252.0 à 2 oktet pertama full (kelas B)
5. Which combination of network id and subnet mask correctly identifies all IP addresses from 172.16.128.0 through 172.16.159.255?
a. 172.16.128.0 and 255.255.255.224
b. 172.16.128.0 and 255.255.0.0
c. 172.16.128.0 and 255.255.192.0
d. 172.16.128.0 and 255.255.224.0
e. 172.16.128.0 and 255.255.255.192
6. Which type of address is 223.168.17.167/29?
a. host address
b. multicast address
c. broadcast address
d. subnetwork address
· Prefik 29 sama dengan subnet mask terakhir 248.
· 256-248 = 8
· Range IP kelipatan 8 didapat IP diatas adalah sebagai broadcast address dari range IP 223.168.17.161 – 223.168.17.166
7. What is the correct number of usable subnetworks and hosts for the IP network address 192.168.99.0 subnetted with a /29 mask?
a. 6 networks / 32 hosts
b. 14 networks / 14 hosts
c. 30 networks / 6 hosts
d. 62 networks / 2 hosts
· Prefix 29 à 11111111.11111111.11111111.11111000 = 255.255.255.248
· Network (bit 1) : 25 = 32 network
· Host (bit 0) : 23-2 = 6 hosts
8. Company XYZ uses a network address of 192.168.4.0. It uses the mask of 255.255.255.224 to create subnets. What is the maximum number of usable hosts in each subnet?
a. 6
b. 14
c. 30
d. 62
· Subnet 255.255.255.224 = 11111111.11111111.11111111.11100000
· Host (bit 0) : 25-2 = 30
9. A company is planning to subnet its network for a maximum of 27 hosts. Which subnet mask would provide the needed hosts and leave the fewest unused addresses in each subnet?
a. 255.255.255.0
b. 255.255.255.192
c. 255.255.255.224
d. 255.255.255.240
e. 255.255.255.248
· Host (bit 0) : 2n-2 ≥ 27
2n ≥ 29
n ≥ 5
11111111.11111111.11111111.11100000 = 255.255.255.224
10. An IP network address has been subnetted so that every subnetwork has 14 usable host IP addresses. What is the appropriate subnet mask for the newly created subnetworks?
a. 255.255.255.128
b. 255.255.255.224
c. 255.255.255.240
d. 255.255.255.248
e. 255.255.255.252
· Host (bit 0) : 2n-2 ≥ 14
2n ≥ 16
n ≥ 4
11111111.11111111.11111111.11110000 = 255.255.255.240
11. A company is using a Class B IP addressing scheme and expects to need as many as 100 networks. What is the correct subnet mask to use with the network configuration?
a. 255.255.0.0
b. 255.255.240.0
c. 255.255.254.0
d. 255.255.255.0
e. 255.255.255.128
f. 255.255.255.192
· Network (bit 1) : 2n ≥ 100
n ≥ 7
11111111.11111111.11111110.00000000 = 255.255.254.0
12. Given a host with the IP address 172.32.65.13 and a default subnet mask, to which network does the host belong?
a. 172.32.65.0
b. 172.32.65.32
c. 172.32.0.0
d. 172.32.32.0
13. What is the subnetwork number of a host with an IP address of 172.16.210.0/22?
a. 172.16.42.0
b. 172.16.107.0
c. 172.16.208.0
d. 172.16.252.0
e. 172.16.254.0
· Prefik 22 à 11111111.11111111.11111100.00000000 = 255.255.252.0
· Subnetwork adalah 172.16.252.0
14. Which of the following IP addresses fall into the CIDR block of 115.64.4.0/22? (Choose three.)
a. 115.64.8.32
b. 115.64.7.64
c. 115.64.6.255
d. 115.64.3.255
e. 115.64.5.128
f. 115.64.12.128
· Prefik 22 à11111111.11111111.11111100.00000000 = 255.255.252.0
· 256-252 = 4
· Range IP kelipatan 4
| Net ID | Range IP | Broadcast |
| 115.64.4.0 | 115.64.4.1 – 115.64.7.254 | 115.64.7.255 |
| 125.64.8.0 | 115.64.8.1 – 115.64.11.254 | 115.64.11.255 |
| 115.64.12.0 | 115.64.12.1 – ……….. | …… |
15. What is the subnetwork address for a host with the IP address 200.10.5.68/28?
a. 200.10.5.56
b. 200.10.5.32
c. 200.10.5.64
d. 200.10.5.0
· Prefix 28 à 11111111.11111111.11111111.11110000 = 255.255.255.240
· 256-240 = 16
· Range IP kelipatan 16.
| Net ID | Range IP | Broadcast |
| 200.10.5.16 | 200.10.5.16 – 200.10.5.16 | 200.10.5.31 |
| 200.10.5.32 | 200.10.5.16 – 200.10.5.16 | 200.10.5.47 |
| 200.10.5.48 | 200.10.5.16 – 200.10.5.166 | 200.10.5.65 |
| 200.10.5.64 | 200.10.5.16 – 200.10.5.16 | 200.10.5.79 |
| 200.10.5.80 | …………… | ………… |
16. The network address of 172.16.0.0/19 provides how many subnets and hosts?
a. 7 subnets, 30 hosts each
b. 7 subnets, 2046 hosts each
c. 7 subnets, 8190 hosts each
d. 8 subnets, 30 hosts each
e. 8 subnets, 2046 hosts each
f. 8 subnets, 8190 hosts each
· Prefiks 19 à1111111.11111111.11100000.00000000
· Network (bit 1) : 23 = 8
· Host (bit 0) : 213 – 2 = 8190
17. You need 500 subnets, each with about 100 usable host addresses per subnet. What mask will you assign using a Class B network address?
a. 255.255.255.252
b. 255.255.255.128
c. 255.255.255.0
d. 255.255.254.0
· Host (bit 0) : 2n-2 ≥ 100
2n ≥ 102
n ≥ 7
11111111.11111111.11111111.1000000 = 255.255.255.128
· Network (bit 1) : 2n ≥ 500
n ≥ 9
11111111.11111111.11111111.1000000 = 255.255.255.128
18. What is the subnetwork number of a host with an IP address of 172.16.66.0/21?
a. 172.16.36.0
b. 172.16.48.0
c. 172.16.64.0
d. 172.16.0.0
· Prefiks 21 à 11111111.11111111.11111000.00000000
· 256 – 248 = 8
· Range IP kelipatan 8
· Subnetwork IP pada subnet 172.16.64.0
19. What mask would you assign to the network ID of 172.16.0.0 if you needed about 100 subnets with about 500 hosts each?
a. 255.255.255.0
b. 255.255.254.0
c. 255.255.252.0
d. 255.255.0.0
· Network (bit 1) : 2n ≥ 100
n ≥ 7
11111111.11111111.11111110.00000000 = 255.255.254.0
· Host (bit 0) : 2n – 2 ≥ 500
2n ≥ 502
n ≥ 9
11111111.11111111.11111110.00000000 = 255.255.254.0
20. You need to configure a server that is on the subnet 192.168.19.24/29. The router has the first available host address. Which of the following should you assign to the server?
a. 192.168.19.0 255.255.255.0
b. 192.168.19.33 255.255.255.240
c. 192.168.19.26 255.255.255.248
d. 192.168.19.31 255.255.255.248
e. 192.168.19.34 255.255.255.240
21. You need a minimum of 300 subnets with a maximum of 50 hosts per subnet. Which of the following masks will support the business requirements? (Choose two.)
a. 255.255.255.0
b. 255.255.255.128
c. 255.255.252.0
d. 255.25.255.224
e. 255.255.255.192
f. 255.255.248.0
· Network (bit 1) : 2n ≥ 300
n ≥ 9
11111111.11111111.11111111.10000000 = 255.255.255.128
· Host (bit 0) : 2n – 2 ≥ 50
2n ≥ 52
n ≥ 6
11111111.11111111.11111111.11000000 = 255.255.255.192
22. If an Ethernet port on a router were assigned an IP address of 172.16.112.1/25, what would be the valid subnet address of this host?
a. 172.16.112.0
b. 172.16.0.0
c. 172.16.96.0
d. 172.16.255.0
e. 172.16.128.0
· Prefiks 25 à11111111.11111111.11111111.10000000 = 255.255.255.128 (subnet mask)
· 256 – 128 = 128
· Subnet valid nya 172.16.112.128
23. Refer to the exhibit. The internetwork in the exhibit has been assigned the IP address 172.20.0.0. What would be the appropriate subnet mask to maximize the number of networks available for future growth?
a. 255.255.224.0
b. 255.255.240.0
c. 255.255.248.0
d. 255.255.252.0
e. 255.255.254.0
· Host (bit 0) : 2n – 2 ≥ 850
2n ≥ 852
n ≥ 10 = 1024
1111111.11111111.11111100.00000000 = 255.255.252.0
24. You have a network with a subnet of 172.16.17.0/22. Which are valid host addresses?
a. 172.16.17.1 255.255.255.252
b. 172.16.0.1 255.255.240.0
c. 172.16.20.1 255.255.254.0
d. 172.16.16.1 255.255.255.240
e. 172.16.18.255 255.255.252.0
f. 172.16.0.1 255.255.255.0
25. Your router has the following IP address on Ethernet0: 172.16.112.1/20. How many hosts can be accommodated on the Ethernet segment?
a. 1024
b. 2046
c. 4094
d. 4096
e. 8190
· Prefiks 20 à 11111111.11111111.11110000.00000000 = 255.255.240.0 (subnet mask)
· Host (bit 0) : 2n – 2 ≥ jumlah host
212 – 2 ≥ 4094
26. You have a /27 subnet mask. Which of the following are valid hosts? (Choose three.)
a. 11.244.18.63
b. 90.10.170.93
c. 143.187.16.56
d. 192.168.15.87
e. 200.45.115.159
f. 216.66.11.192
27. You have a Class B network ID and need about 450 IP addresses per subnet. What is the best mask for this network?
a. 255.255.240.0
b. 255.255.248.0
c. 255.255.254.0
d. 255.255.255.0
· Host (bit 0) : 2n – 2 ≥ 450
2n ≥ 452
n ≥ 9 = 512
11111111.11111111.11111110.00000000 = 255.255.254.0
28. Host A is connected to the LAN, but it cannot connect to the Internet. The host configuration is shown in the exhibit. What are the two problems with this configuration? (Choose two.)
a. The host subnet mask is incorrect.
b. The host is not configured for subnetting.
c. The default gateway is a network address.
d. The default gateway is on a different network than the host.
e. The host IP address is on a different network from the Serial interface of the router.
· Prefiks 27 à 11111111.11111111.11111111.11100000 = 255.255.255.224 (subnet mask)
· 256 – 224 = 32
· Range IP kelipatan 32.
· Address host:
| Net ID | Range IP | Broadcast |
| 192.18.166.32 | 192.18.166.33 – 192.18.166.62 | 192.18.166.63 |
| 192.18.166.64 | 192.18.166.65 – 192.18.166.94 | 192.18.166.95 |
| 192.18.166.96 | 192.18.166.97 – 192.18.166.126 | 192.18.166.127 |
