Subnetting Questions Flashcards
Subnet Zero
In the past, this website also provided questions relating to old routing kit that did not allow the use of the all “1” subnet or all the “0” subnet (known as ‘subnet zero’). The majority of site users are revising for cisco exams so the questions have been removed to avoid confusion.
On this website, and on all new cisco routers, the number of subnets is calculated using the formula of 2^n by default. However, for legacy routers network engineers use 2^n - 2 to comply with the almost obselete RFC 1878 standard. Some text books and courses that relate to old routing equipment also refer to the old formula as do some Microoft Learning courses. If you’re planning to take a non-Cisco exam that involves subnetting you should make sure you understand the ‘subnet zero’ concept’ and check what is considered the default correct formula by your examining board. Cisco’s position on subnet zero is stated here.
Question: What is the first valid host on the subnetwork that the node 172.24.159.244 255.255.254.0 belongs to?
Answer: 172.24.158.1
Question: What is the first valid host on the subnetwork that the node 172.29.24.25/25 belongs to?
Answer: 172.29.24.1
Question: What is the first valid host on the subnetwork that the node 172.21.155.145/23 belongs to?
Answer: 172.21.154.1
Question: Which subnet does host 172.17.254.166 255.255.255.192 belong to?
Answer: 172.17.254.128
Question: Which subnet does host 172.28.39.245 255.255.254.0 belong to?
Answer: 172.28.38.0
Question: What is the broadcast address of the network 172.18.236.0 255.255.252.0?
Answer: 172.18.239.255
Question: Which subnet does host 172.20.6.188 255.255.254.0 belong to?
Answer: 172.20.6.0
Question: What is the last valid host on the subnetwork 192.168.155.168 255.255.255.248?
Answer: 192.168.155.174
Question: What valid host range is the IP address 172.30.167.104/24 a part of?
Answer: 172.30.167.1 through to 172.30.167.254
Question: What valid host range is the IP address 10.141.252.111 255.255.240.0 a part of?
Answer: 10.141.240.1 through to 10.141.255.254
Question: What is the broadcast address of the network 192.168.103.60/30?
Answer: 192.168.103.63
Question: What is the broadcast address of the network 172.22.160.0/21?
Answer: 172.22.167.255
Question: Which subnet does host 10.19.53.68 255.255.240.0 belong to?
Answer: 10.19.48.0
Question: Which subnet does host 192.168.112.14 255.255.255.248 belong to?
Answer: 192.168.112.8
Question: What valid host range is the IP address 192.168.124.209 255.255.255.240 a part of?
Answer: 192.168.124.209 through to 192.168.124.222
Question: What is the last valid host on the subnetwork 172.28.3.0/27?
Answer: 172.28.3.30
Question: What valid host range is the IP address 10.120.130.20 255.255.240.0 a part of?
Answer: 10.120.128.1 through to 10.120.143.254
Question: What is the broadcast address of the network 172.18.152.0/21?
Answer: 172.18.159.255
Question: How many subnets and hosts per subnet can you get from the network 192.168.108.0 255.255.255.240?
Answer: 16 subnets and 14 hosts
Question: Which subnet does host 172.29.38.150 255.255.252.0 belong to?
Answer: 172.29.36.0
Question: What is the last valid host on the subnetwork 172.28.172.128 255.255.255.128?
Answer: 172.28.172.254
Question: What is the last valid host on the subnetwork 10.206.224.0 255.255.240.0?
Answer: 10.206.239.254
Question: Which subnet does host 192.168.149.160/26 belong to?
Answer: 192.168.149.128
Question: Which subnet does host 192.168.3.212 255.255.255.240 belong to?
Answer: 192.168.3.208
Question: Which subnet does host 192.168.101.6/28 belong to?
Answer: 192.168.101.0
Question: What valid host range is the IP address 192.168.37.156 255.255.255.240 a part of?
Answer: 192.168.37.145 through to 192.168.37.158
Question: What is the first valid host on the subnetwork that the node 192.168.101.36 255.255.255.224 belongs to?
Answer: 192.168.101.33
Question: Which subnet does host 172.22.123.211/23 belong to?
Answer: 172.22.122.0
Question: Which subnet does host 172.19.231.63 255.255.240.0 belong to?
Answer: 172.19.224.0
Question: Which subnet does host 172.24.114.79/23 belong to?
Answer: 172.24.114.0
Question: What is the broadcast address of the network 10.27.16.0/20?
Answer: 10.27.31.255
Question: Which subnet does host 172.16.123.219 255.255.254.0 belong to?
Answer: 172.16.122.0
Question: How many subnets and hosts per subnet can you get from the network 172.19.0.0/23?
Answer: 128 subnets and 510 hosts
Question: How many subnets and hosts per subnet can you get from the network 172.26.0.0 255.255.254.0?
Answer: 128 subnets and 510 hosts
Question: What is the last valid host on the subnetwork 192.168.26.164/30?
Answer: 192.168.26.166
Question: What is the broadcast address of the network 172.16.128.64/27?
Answer: 172.16.128.95
Question: What is the last valid host on the subnetwork 172.20.108.0/23?
Answer: 172.20.109.254
Question: What is the broadcast address of the network 192.168.19.64 255.255.255.192?
Answer: 192.168.19.127
Question: How many subnets and hosts per subnet can you get from the network 172.29.0.0/25?
Answer: 512 subnets and 126 hosts
Question: What is the last valid host on the subnetwork 172.26.109.64 255.255.255.192?
Answer: 172.26.109.126
Question: How many subnets and hosts per subnet can you get from the network 172.20.0.0/20?
Answer: 16 subnets and 4094 hosts
Question: What is the last valid host on the subnetwork 172.24.248.0/21?
Answer: 172.24.255.254
Question: You are designing a subnet mask for the 172.20.0.0 network. You want 2400 subnets with up to 8 hosts on each subnet. What subnet mask should you use?
Answer: 255.255.255.240
Question: Which subnet does host 10.156.136.17 255.255.240.0 belong to?
Answer: 10.156.128.0
Question: What is the first valid host on the subnetwork that the node 192.168.247.94 255.255.255.240 belongs to?
Answer: 192.168.247.81
Question: You are designing a subnet mask for the 172.29.0.0 network. You want 900 subnets with up to 50 hosts on each subnet. What subnet mask should you use?
Answer: 255.255.255.192
Question: What is the last valid host on the subnetwork 172.18.192.0 255.255.254.0?
Answer: 172.18.193.254
Question: How many subnets and hosts per subnet can you get from the network 172.18.0.0 255.255.252.0?
Answer: 64 subnets and 1022 hosts
Question: What is the first valid host on the subnetwork that the node 172.31.212.129/26 belongs to?
Answer: 172.31.212.129
Question: What is the first valid host on the subnetwork that the node 172.27.119.100 255.255.255.192 belongs to?
Answer: 172.27.119.65
Question: What is the broadcast address of the network 172.23.54.0 255.255.254.0?
Answer: 172.23.55.255
Question: How many subnets and hosts per subnet can you get from the network 172.30.0.0/27?
Answer: 2048 subnets and 30 hosts
Question: What valid host range is the IP address 172.24.174.81/23 a part of?
Answer: 172.24.174.1 through to 172.24.175.254
Question: What valid host range is the IP address 10.121.14.234 255.255.240.0 a part of?
Answer: 10.121.0.1 through to 10.121.15.254
Question: What valid host range is the IP address 172.30.245.122 255.255.248.0 a part of?
Answer: 172.30.240.1 through to 172.30.247.254
Question: What is the first valid host on the subnetwork that the node 172.27.89.12 255.255.248.0 belongs to?
Answer: 172.27.88.1
Question: What is the first valid host on the subnetwork that the node 172.31.66.156/21 belongs to?
Answer: 172.31.64.1
Question: What is the first valid host on the subnetwork that the node 172.24.76.114 255.255.255.240 belongs to?
Answer: 172.24.76.113
Question: You are designing a subnet mask for the 172.27.0.0 network. You want 120 subnets with up to 400 hosts on each subnet. What subnet mask should you use?
Answer: 255.255.254.0
Question: How many subnets and hosts per subnet can you get from the network 192.168.109.0/29?
Answer: 32 subnets and 6 hosts
Question: You are designing a subnet mask for the 10.0.0.0 network. You want 4000 subnets with up to 3000 hosts on each subnet. What subnet mask should you use?
Answer: 255.255.240.0
Question: What is the first valid host on the subnetwork that the node 172.18.211.242/28 belongs to?
Answer: 172.18.211.241
Question: What is the broadcast address of the network 172.21.58.0/23?
Answer: 172.21.59.255
Question: What is the last valid host on the subnetwork 192.168.174.192 255.255.255.192?
Answer: 192.168.174.254
Question: What is the first valid host on the subnetwork that the node 172.25.186.51 255.255.255.128 belongs to?
Answer: 172.25.186.1
Question: What is the broadcast address of the network 192.168.217.128/26?
Answer: 192.168.217.191
Question: You are designing a subnet mask for the 192.168.104.0 network. You want 15 subnets with up to 8 hosts on each subnet. What subnet mask should you use?
Answer: 255.255.255.240
Question: What valid host range is the IP address 10.206.153.5/20 a part of?
Answer: 10.206.144.1 through to 10.206.159.254
Answer: 10.206.144.1 through to 10.206.159.254
Question: Which subnet does host 192.168.199.70/30 belong to?
Answer: 192.168.199.68
Answer: 192.168.199.68
Question: What is the last valid host on the subnetwork 172.29.32.0 255.255.254.0?
Answer: 172.29.33.254
Question: What is the broadcast address of the network 10.10.128.0 255.255.240.0?
Answer: 10.10.143.255
Question: What is the broadcast address of the network 172.20.239.0 255.255.255.128?
Answer: 172.20.239.127
Question: What is the first valid host on the subnetwork that the node 172.25.148.179 255.255.255.128 belongs to?
Answer: 172.25.148.129
Question: You are designing a subnet mask for the 10.0.0.0 network. You want 2900 subnets with up to 2200 hosts on each subnet. What subnet mask should you use?
Answer: 255.255.240.0
Question: What valid host range is the IP address 172.21.227.46/25 a part of?
Answer: 172.21.227.1 through to 172.21.227.126
Question: Which subnet does host 10.198.233.93/20 belong to?
Answer: 10.198.224.0
Question: How many subnets and hosts per subnet can you get from the network 172.29.0.0/25?
Answer: 512 subnets and 126 hosts
Question: What is the first valid host on the subnetwork that the node 192.168.182.252/25 belongs to?
Answer: 192.168.182.129
Question: How many subnets and hosts per subnet can you get from the network 192.168.120.0 255.255.255.240?
Answer: 16 subnets and 14 hosts
Question: What is the broadcast address of the network 172.19.168.192 255.255.255.192?
Answer: 172.19.168.255
Question: What valid host range is the IP address 172.18.124.54 255.255.254.0 a part of?
Answer: 172.18.124.1 through to 172.18.125.254
Question: How many subnets and hosts per subnet can you get from the network 172.17.0.0 255.255.255.0?
Answer: 256 subnets and 254 hosts
Question: You are designing a subnet mask for the 172.22.0.0 network. You want 1100 subnets with up to 30 hosts on each subnet. What subnet mask should you use?
Answer: 255.255.255.224
Question: What is the first valid host on the subnetwork that the node 172.16.246.145/22 belongs to?
Answer: 172.16.244.1
Question: Which subnet does host 172.21.74.135 255.255.255.0 belong to?
Answer: 172.21.74.0
Question: Which subnet does host 172.16.27.93/20 belong to?
Answer: 172.16.16.0
Question: What is the last valid host on the subnetwork 172.25.66.0/23?
Answer: 172.25.67.254
Question: What is the last valid host on the subnetwork 172.18.168.0 255.255.248.0?
Answer: 172.18.175.254
Question: What is the last valid host on the subnetwork 172.18.214.0 255.255.254.0?
Answer: 172.18.215.254
Question: What is the first valid host on the subnetwork that the node 192.168.128.61/25 belongs to?
Answer: 192.168.128.1
Question: What is the last valid host on the subnetwork 172.26.154.0 255.255.255.0?
Answer: 172.26.154.254
Question: How many subnets and hosts per subnet can you get from the network 172.29.0.0/26?
Answer: 1024 subnets and 62 hosts
Question: Which subnet does host 192.168.29.219 255.255.255.240 belong to?
Answer: 192.168.29.208
Question: How many subnets and hosts per subnet can you get from the network 172.20.0.0 255.255.240.0?
Answer: 16 subnets and 4094 hosts
Question: What is the broadcast address of the network 10.37.16.0 255.255.240.0?
Answer: 10.37.31.255
Question: What valid host range is the IP address 192.168.145.236/28 a part of?
Answer: 192.168.145.225 through to 192.168.145.238
Question: How many subnets and hosts per subnet can you get from the network 172.19.0.0/22?
Answer: 64 subnets and 1022 hosts
Question: How many subnets and hosts per subnet can you get from the network 172.19.0.0/23?
Answer: 128 subnets and 510 hosts
Question: Which subnet does host 172.27.116.168/23 belong to?
Answer: 172.27.116.0