How many usable hosts in a /26?

62. The formula is 2 to the power of the host bits, minus 2: a /26 leaves 6 host bits, so 64 addresses minus network and broadcast gives 62 usable hosts.

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Subnet calculator + practice

Solve any network, watch the 32 bits split into network and host, then drill random problems until the method is automatic. The worked steps show the exact problem in front of you, not a generic example.

Subnet calculator

Type and the bits update

IP addressPrefix or mask

Network bits 26Host bits 6Bits read left to right. The line shows where the mask cuts.

Octet 1192

11000000

Octet 2168

10101000

Octet 31

00000001

Octet 410

00001010

Subnet mask: 255.255.255.192
Wildcard: 0.0.0.63
Network: 192.168.1.0
Broadcast: 192.168.1.63
First usable: 192.168.1.1
Last usable: 192.168.1.62
Next network: 192.168.1.64
Usable hosts: 62
Class: C
Private range: Yes (RFC 1918)

Practice: 192.168.2.128/24

Session: 0/0 fields right

Streak readyBest: 0 problems. All five fields must be right.

Network IDBroadcastFirst hostLast hostNext network

How subnetting actually works

An IPv4 address is 32 bits. The CIDR number (the /24) says how many of those bits name the network; the rest name hosts inside it. To find the network, write the mask (24 ones, then zeros), AND it with the address, and the network falls out.

The exam method (no binary needed)

Find the interesting octet. The one where the mask is neither 0 nor 255. For /26 the mask is 255.255.255.192, so the 4th octet is interesting.
The block size is 256 minus the mask value: 256 − 192 = 64. Networks start at multiples of the block: 0, 64, 128, 192.
Find the multiple your address falls in. That is the network. Broadcast is one before the next network; usable hosts sit between.

Worked example: 192.168.1.10/26

Mask 255.255.255.192, block size 64. Multiples: 0, 64, 128, 192, 256. Address .10 falls in 0-63, so the network is 192.168.1.0, broadcast 192.168.1.63, usable 192.168.1.1 to 192.168.1.62 (62 hosts). Try it in the calculator, then drill until it takes under 30 seconds.

Practice this in the app

Free to start. No card.

Read the subnetting lessonNetwork+ path: addressing and CIDR Try a subnetting labApply the method to a design task

Subnetting questions

Subnetting splits a large IP network into smaller ones by borrowing host bits for the network portion. The CIDR number (like /24) says how many of the 32 address bits identify the network. Exams test whether you can find the network, broadcast, usable range, and next network for any address. The drill below trains exactly that.

Subnetting is one Network+ topic of twenty-five

SecLern drills all of them: VLANs, wireless, troubleshooting, and full simulations. Sessions are aimed at your gaps. The subnet habit you built here transfers straight in.

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