What a /26 subnet is: a quarter of a /24
A /26 holds 64 addresses, 62 usable, and divides a /24 into four equal subnets at .0, .64, .128 and .192.
At a glance
- Subnet mask
- 255.255.255.192
- Wildcard mask
- 0.0.0.63
- Total addresses
- 64
- Usable hosts
- 62
- Block size in the last octet
- 64
- Host bits
- 6 of 32
In detail
The mask is 255.255.255.192. Sixty two usable hosts is enough for a normal department or a small server tier, and the boundaries are easy to hold in your head.
A common size in cloud subnets where each availability zone gets its own block, and in campus designs where each closet gets a quarter of a /24.
In a cloud virtual network, check how many addresses the provider reserves in each subnet before sizing. Several reserve five rather than two, which leaves 59 rather than 62 in a /26.
Examples
10.0.9.0/26 .0 to .63 usable .1 to .62
10.0.9.64/26 .64 to .127 usable .65 to .126
10.0.9.128/26 .128 to .191 usable .129 to .190
10.0.9.192/26 .192 to .255 usable .193 to .254Things that catch people out
- The block size in the last octet is 64, so the only valid /26 network addresses end in 0, 64, 128 or 192.
- A /26 that fills up cannot simply be widened to a /25 unless the neighbouring /26 is free and the block starts at .0 or .128.
Try it: IP Subnet Calculator
Enter any IPv4 address with a prefix or a dotted mask and get the network address, broadcast address, wildcard mask, usable host range, address class, and the hex and binary forms.
IP Subnet Calculator
LOCAL · Browser-OnlyCalculate IP subnet details, network ranges, and CIDR notation
192.168.1.0192.168.1.255255.255.255.00.0.0.255192.168.1.0/24192.168.1.1 - 192.168.1.254192.168.1.1192.168.1.254256254C0xC0A8016411000000.10101000.00000001.01100100Split into two /25 subnets
Dividing 192.168.1.0/24 one prefix deeper.
Common Subnet Masks
Related IPv4 subnets
All ipv4 subnets →What a /24 subnet is: the classic LAN subnet
A /24 uses the mask 255.255.255.0 and gives 254 usable addresses. What it is for and where it goes wrong.
What a /27 subnet is: an eighth of a /24
A /27 uses the mask 255.255.255.224 and gives 30 usable addresses. What it is for and where it goes wrong.
What a /25 subnet is: half a /24
A /25 uses the mask 255.255.255.128 and gives 126 usable addresses. What it is for and where it goes wrong.
What a /28 subnet is: sixteen addresses
A /28 uses the mask 255.255.255.240 and gives 14 usable addresses. What it is for and where it goes wrong.
What a /29 subnet is: eight addresses
A /29 uses the mask 255.255.255.248 and gives 6 usable addresses. What it is for and where it goes wrong.
What a /30 subnet is: a point-to-point link
A /30 uses the mask 255.255.255.252 and gives 2 usable addresses. What it is for and where it goes wrong.
Tools for this
- IP Subnet Calculator Free online IP subnet calculator - calculate IP subnet details, CIDR notation, and network address ranges
- IP Address Lookup Free online IP address lookup - find your public IP address and basic network information
- Number Base Converter Free online number base converter - convert numbers between decimal, binary, octal, and hexadecimal