172.16.0.0/12 IP Range
First and last address, mask and host count for 172.16.0.0/12.
The middle RFC 1918 private block. It is not 172.16.0.0/16: it spans 172.16.0.0 through 172.31.255.255.
| CIDR | 172.16.0.0/12 |
|---|---|
| Network address | 172.16.0.0 |
| Subnet mask | 255.240.0.0 |
| Wildcard mask | 0.15.255.255 |
| First usable IP | 172.16.0.1 |
| Last usable IP | 172.31.255.254 |
| Broadcast address | 172.31.255.255 |
| Total addresses | 1,048,576 |
| Usable hosts | 1,048,574 |
How it is used
Docker's default bridge network, 172.17.0.0/16, falls inside this block, so a company network that also uses 172.16.0.0/12 can clash with containers on the same host. Check for overlap before joining a VPN.
Allow this range in a firewall
sudo iptables -I INPUT 1 -p tcp -s 172.16.0.0/12 --dport 22 -j ACCEPT
This lets the whole range reach SSH. Change the port as needed, or build a complete rule set with the allow a port from specific IPs tool.
Calculate another range
Use the CIDR to IP range calculator for any other network.
FAQ
How many usable hosts are in 172.16.0.0/12?
1,048,574 usable addresses out of 1,048,576 total. The network and broadcast addresses are reserved.
Which addresses does 172.16.0.0/12 cover?
172.16.0.0 to 172.31.255.255, which is sixteen /16 networks.
Is 172.16.0.0/12 a private range?
Yes. It belongs to the private address space defined in RFC 1918 and is not routed on the public internet.