1.
Subnet the IP Address 203.10.93.0 /24 into 30 Subnets. Is 203.10.93.30 a valid Host ID after subnetting?
Correct Answer
A. Yes
Explanation
To subnet the IP address 203.10.93.0/24 into 30 subnets, you need to borrow enough bits to accommodate at least 30 subnets. In binary, 5 bits can represent 2^5 = 32 subnets, so you would need to borrow 5 bits. This results in a subnet mask of /29 (32 - 5 = 27, so the new subnet mask is 24 + 5 = 29).
So, the subnetted network addresses would be in the form of 203.10.93.X/29, where X represents the subnet number.
Now, to check if 203.10.93.30 is a valid host ID in one of the subnets, you need to look at the range of valid host IDs in one of the subnets. For a /29 subnet, the valid host IDs are 203.10.93.25 to 203.10.93.30. Therefore, 203.10.93.30 is a valid host ID in one of the subnets.
So, the answer is Yes.
2.
You are given the IP Address of 193.103.20.0 /24 and need 50 Subnets. How many hosts per network, and total networks do you get once subnetted?
Correct Answer
D. 2 Hosts and 64 Subnets
Explanation
To create 50 subnets from a 193.103.20.0 /24 address, you need to borrow bits from the host part to increase the number of subnets. Borrowing 6 bits from the original 24-bit subnet mask gives you a /30 subnet mask. This allows for 64 subnets in total, with each subnet having 4 IP addresses. However, because one address is used as the network address and another as the broadcast address in each subnet, only 2 addresses in each subnet are available for hosts. So, you end up with 64 subnets, each capable of hosting 2 devices.
3.
Your company has been given the IP Address of 199.2.1.0 /24 to the subnet. You plan to put each of the 5 floors in your building on its own subnet. What is the IP range of the LAST available network once your subnet?
Correct Answer
D. 199.2.1.128 - 199.2.1.159
Explanation
1st subnet: 199.2.1.0 - 199.2.1.31
2nd subnet: 199.2.1.32 - 199.2.1.63
3rd subnet: 199.2.1.64 - 199.2.1.95
4th subnet: 199.2.1.96 - 199.2.1.127
5th subnet: 199.2.1.128 - 199.2.1.159 (This is the last available network)
So, the IP range of the last available network is from 199.2.1.128 to 199.2.1.159.
4.
Subnet the Class B IP Address 130.13.0.0 into 500 Subnets. What is the new Subnet Mask, and what is the Increment?
Correct Answer
C. Subnet Mask 255.255.255.128 with an Increment of 128
Explanation
To subnet the Class B IP address 130.13.0.0 into 500 subnets, you need to use a subnet mask of 255.255.255.128, and each subnet will have an increment of 128 host addresses. This allows you to create 500 smaller subnetworks from the original Class B address while providing a sufficient number of host addresses in each subnet.
5.
Your company wants to utilize the private Class C IP Address of 192.168.1.0. You are tasked with Subnetting the Address to get the most networks with at least 30 Hosts per Subnet. How many Networks will be created after you subnet? Also, what is the first usable IP Address in the Second Network range?
Correct Answer
A. 8 Networks, First usable from second Network range = 192.168.1.33
Explanation
192.168.1.0 Need 30 Hosts per Network 128 64 32 16 8 4 2 1 0 0 0 1 1 1 1 0 = 30 in binary Need to save 5 bits for # of Hosts New Subnet Mask = 255.255.255.11100000 (224) or /27 ^ Increment = 32 2^3 = # of Networks = 8 2^5-2 = # of Hosts per Network = 30 First 5 IP Ranges 192.168.1.0 - 192.168.1.31 1.32 – 1.63 1.64 – 1.95 1.96 – 1.127 1.128 – 1.159
6.
Subnet the Address 150.20.0.0 into networks supporting 500 Hosts each. What is the New Subnet Mask and the IP Address Range of the first Network?
Correct Answer
D. Subnet mask: 255.255.254.0, range: 150.20.0.1 to 150.20.1.254
Explanation
To subnet the address 150.20.0.0 into networks supporting 500 hosts each, we need to determine the appropriate subnet mask and calculate the IP address range for the first network.
To support 500 hosts, we need to find the smallest subnet that accommodates at least 500 host addresses. This requires 9 bits for host addresses (2^9 = 512, which is more than 500), leaving the remaining bits for the network portion.
Since the original address 150.20.0.0 is a Class B address, it has a default subnet mask of /16 (255.255.0.0). To support 500 hosts, we need to borrow 9 bits for host addresses, leaving 7 bits for the network portion in the subnet mask.
The new subnet mask will be /23, which corresponds to 255.255.254.0 (because 8 bits in the third octet plus the first bit of the fourth octet make up 9 bits in total).
For the IP address range of the first network, we'll consider the subnet address and the range of host addresses.
Subnet Address: 150.20.0.0 (Given)
First IP Address in Range: This will be the subnet address + 1, which is 150.20.0.1.
Last IP Address in Range: We calculate the last IP address by subtracting 1 from the broadcast address of the subnet. The broadcast address is the highest address in the subnet range. Since we borrowed 9 bits for hosts, the broadcast address will end in 11111111, or 255 in decimal, in the third octet and 254 in the fourth octet. So, the broadcast address is 150.20.1.255. Therefore, the last usable IP address in the range is 150.20.1.254.
So, for the first network:
Subnet mask: 255.255.254.0 (/23)
IP address range: 150.20.0.1 to 150.20.1.254
7.
Subnet the IP Address 210.30.12.0, so there are 60 Hosts in each network. What are the Broadcast Addresses of each Network?
Correct Answer
A. 210.30.12.63, 127, 191, and 255
Explanation
210.30.12.0 Need 60 Hosts per Network 128 64 32 16 8 4 2 1 0 0 1 1 1 1 0 0 = 60 in binary Need to save 6 bits for # of Hosts New Subnet Mask = 255.255.255.11000000 (192) or /26 ^ Increment = 64 2^2 = # of Networks = 4 2^6-2 = # of Hosts per Network = 62 All 4 IP Ranges 210.30.12.0 - 210.30.12.63 12.64 – 12.127 12.128 – 12.191 12.192 – 12.255
8.
Your ISP has given you the address 223.5.14.6/29 to assign to your router’s interface. They have also given you the default gateway address of 223.5.14.7. After you have configured the address, the router is unable to ping any remote devices. What is preventing the router from pinging remote devices?
Correct Answer
A. The default gateway is not an address on this subnet.
Explanation
The default gateway address (223.5.14.7) provided by the ISP is outside the range of usable IP addresses in the subnet (223.5.14.0/29), which only includes addresses from 223.5.14.1 to 223.5.14.6. Therefore, the router cannot effectively route traffic to remote devices.
9.
Given the address 192.168.20.19/28, which of the following are valid host addresses on this subnet? (Choose two)
Correct Answer(s)
A. 192.168.20.29
C. 192.168.20.17
Explanation
The given address 192.168.20.19/28 has a subnet mask of 28 bits, which means that the first 28 bits of the IP address are used for the network portion and the remaining 4 bits are used for the host portion.
The valid host addresses on this subnet are those that have the same network portion (first 28 bits) as the given address, but different host portions.
Out of the given options, 192.168.20.29 and 192.168.20.17 have the same network portion as 192.168.20.19 but different host portions, making them valid host addresses on this subnet.
Therefore, the correct answers are 192.168.20.29 and 192.168.20.17.
10.
How many subnets can be gained by subnetting 172.17.32.0/23 into a /27 mask, and how many usable host addresses will there be per subnet?
Correct Answer
C. 16 subnets, 30 hosts
Explanation
By subnetting the network 172.17.32.0/23 into a /27 mask, we are borrowing 4 bits from the host portion to create subnets. With 4 borrowed bits, we can create 2^4 = 16 subnets. However, since the /27 mask only allows for 5 host bits, we have 2^5 - 2 = 30 usable host addresses per subnet (subtracting 2 for the network and broadcast addresses). Therefore, the correct answer is 16 subnets, 30 hosts.