A subnet mask helps a device determine which IP addresses are on its local network and which should be reached through a router.
Step by Step
- Open your network details or run ipconfig.
- Find Subnet Mask beside the IPv4 configuration.
- A common home-network mask is 255.255.255.0, though networks can use many other sizes.
- Normally your router's DHCP service supplies this automatically.
If That Doesn't Work
- Do not manually change subnet settings unless you know the network configuration.
- An incorrect subnet mask can prevent devices from reaching local or remote destinations.