How many IPS is a 26?
64 IPv4 addresses
A “/26” network provides 64 IPv4 addresses.
How many addresses are in a 30?
Subnet Cheat Sheet – 24 Subnet Mask, 30, 26, 27, 29, and other IP Address CIDR Network References
| CIDR | Subnet mask | # of usable IP addresses |
|---|---|---|
| /30 | 255.255.255.252 | 2 |
| /29 | 255.255.255.248 | 6 |
| /28 | 255.255.255.240 | 14 |
| /27 | 255.255.255.224 | 30 |
When to use a wildcard mask in a network?
A network and wildcard mask combination of 1.1.1.1 0.0.0.0 would match an interface configured exactly with 1.1.1.1 only, and nothing else. Wildcard masks are used in situations where subnet masks may not apply. For example, when two affected hosts fall in different subnets, the use of a wildcard mask will group them together.
How to figure out the CIDR notation for a subnet mask?
For instance, the /24 in 192.168.0.101/24 is equivalent to the IP address 192.168.0.101 and the subnet mask 255.255.255.0. To figure out the CIDR notation for a given subnet mask, all you need to do is convert the subnet mask into binary, then count the number of ones or “on” digits.
Where does the CIDR number come from in binary?
The CIDR number comes from the number of ones in the subnet mask when converted to binary. The common subnet mask 255.255.255.0 is 11111111.11111111.11111111.00000000 in binary. This adds up to 24 ones, or /24 (pronounced ‘slash twenty four’). A subnet mask of 255.255.255.192 is 11111111.11111111.11111111.11000000 in binary, or 26 ones, hence /26.
What is the CIDR notation for 192.168.0.101?
So the CIDR notation of the IP address 192.168.0.101 with a subnet mask of 255.255.255.0 is 192.168.0.0/24. To see more examples of how to calculate the CIDR notation and network ID for a given IP address and subnet mask, check out this video: IPv4 Addressing Lesson 2: Network IDs and Subnet Masks