Subnet cidr form

Here is a list of common subnet CIDR forms:

• /32: 1 IP address, 1 subnet mask (255.255.255.255)
• /31: 2 IP addresses, 1 subnet mask (255.255.255.254)
• /30: 4 IP addresses, 1 subnet mask (255.255.255.252)
• /29: 8 IP addresses, 1 subnet mask (255.255.255.248)
• /28: 16 IP addresses, 1 subnet mask (255.255.255.240)
• /27: 32 IP addresses, 1 subnet mask (255.255.255.224)
• /26: 64 IP addresses, 1 subnet mask (255.255.255.192)
• /25: 128 IP addresses, 1 subnet mask (255.255.255.128)
• /24: 256 IP addresses, 1 subnet mask (255.255.255.0)
• /23: 512 IP addresses, 1 subnet mask (255.255.254.0)
• /22: 1,024 IP addresses, 1 subnet mask (255.255.252.0)
• /21: 2,048 IP addresses, 1 subnet mask (255.255.248.0)
• /20: 4,096 IP addresses, 1 subnet mask (255.255.240.0)
• /19: 8,192 IP addresses, 1 subnet mask (255.255.224.0)
• /18: 16,384 IP addresses, 1 subnet mask (255.255.192.0)
• /17: 32,768 IP addresses, 1 subnet mask (255.255.128.0)
• /16: 65,536 IP addresses, 1 subnet mask (255.255.0.0)
• /15: 131,072 IP addresses, 1 subnet mask (255.254.0.0)
• /14: 262,144 IP addresses, 1 subnet mask (255.252.0.0)
• /13: 524,288 IP addresses, 1 subnet mask (255.248.0.0)
• /12: 1,048,576 IP addresses, 1 subnet mask (255.240.0.0)
• /11: 2,097,152 IP addresses, 1 subnet mask (255.224.0.0)
• /10: 4,194,304 IP addresses, 1 subnet mask (255.192.0.0)
• /9: 8,388,608 IP addresses, 1 subnet mask (255.128.0.0)
• /8: 16,777,216 IP addresses, 1 subnet mask (255.0.0.0)
• /7: 33,554,432 IP addresses, 1 subnet mask (254.0.0.0)
• /6: 67,108,864 IP addresses, 1 subnet mask (252.0.0.0)
• /5: 134,217,728 IP addresses, 1 subnet mask (248.0.0.0)
• /4: 268,435,456 IP addresses, 1 subnet mask (240.0.0.0)
• /3: 536,870,912 IP addresses, 1 subnet mask (224.0.0.0)
• /2: 1,073,741,824 IP addresses, 1 subnet mask (192.0.0.0)
• /1: 2,147,483,648 IP addresses, 1 subnet mask (128.0.0.0)
• Note that the number of IP addresses available in each subnet decreases as the CIDR value increases.