A /16 is the old Class B size: two octets fixed, 65,534 usable hosts. Two well-known /16s matter on a Mac. 192.168.0.0/16 is the private range most home routers draw from. 169.254.0.0/16 is link-local: if your Mac shows a 169.254.x.x address, it didn’t get one from DHCP and assigned itself one. In AWS, /16 is the largest CIDR block a VPC can have.
Facts
- Prefix
- /16
- Subnet mask
- 255.255.0.0
- Wildcard mask
- 0.0.255.255
- Binary mask
- 11111111.11111111.00000000.00000000
- Total addresses
- 65,536
- Usable hosts
- 65,534
- Example range
- 10.0.0.0/16: 10.0.0.0 – 10.0.255.255
- Typical use
- The private 192.168.0.0/16 range, link-local 169.254.0.0/16, and the largest AWS VPC.
Try it
Try: , ,
- CIDR block
- 10.0.0.0/16
- IP range
- 10.0.0.0 – 10.0.255.255
- Addresses
- 65,536
- Usable hosts
- 65,534
- Subnet mask
- 255.255.0.0
- Wildcard mask
- 0.0.255.255
Frequently asked questions
How many hosts are in a /16?
A /16 has 65,536 addresses. Subtracting the network and broadcast addresses leaves 65,534 usable hosts.
What is the subnet mask for /16?
/16 is 255.255.0.0 (wildcard mask 0.0.255.255). In binary that’s 16 ones followed by 16 zeros.