Networking & IT Tools
Wildcard Mask Calculator
Enter a CIDR prefix to calculate its subnet mask and wildcard mask, used in Cisco ACLs and OSPF configuration.
255.255.255.0
Subnet mask
0.0.0.255
Wildcard mask (used in Cisco ACLs)
How to use this tool
- 1Set the CIDR prefix.
- 2See the subnet mask and its wildcard (inverse) mask.
Frequently asked questions
What is a wildcard mask used for?+
Wildcard masks are the inverse of subnet masks, used in Cisco access control lists (ACLs) and OSPF network statements to match address ranges.