Wildcard Mask Calculator
Enter a subnet mask or wildcard mask to instantly convert between the two formats for Cisco ACL and OSPF configuration. Get the inverse mask, matching IP range, and access list notation — essential for writing Cisco IOS access control lists, OSPF network statements, and router filter rules. Use the ip address validator to verify IP addresses from firewall configurations, DNS records, or access control lists.
Subnet Mask to Wildcard
Wildcard to Subnet Mask
Binary Representation
Cisco Command Examples
Common Wildcard Masks
| CIDR | Subnet Mask | Wildcard Mask | Hosts |
|---|---|---|---|
| /8 | 255.0.0.0 | 0.255.255.255 | 16,777,214 |
| /16 | 255.255.0.0 | 0.0.255.255 | 65,534 |
| /24 | 255.255.255.0 | 0.0.0.255 | 254 |
| /25 | 255.255.255.128 | 0.0.0.127 | 126 |
| /26 | 255.255.255.192 | 0.0.0.63 | 62 |
| /27 | 255.255.255.224 | 0.0.0.31 | 30 |
| /28 | 255.255.255.240 | 0.0.0.15 | 14 |
| /29 | 255.255.255.248 | 0.0.0.7 | 6 |
| /30 | 255.255.255.252 | 0.0.0.3 | 2 |
| /32 | 255.255.255.255 | 0.0.0.0 | 1 |
Related Network Tools
Explore these related tools for subnet calculation and IP address management. Use the ip subnet calculator to determine the CIDR equivalent and host range when you have an IP address and subnet mask pair.
Additional networking calculators for IP address planning and network analysis. Use the subnet mask tool to quickly determine the subnet mask for any /prefix value including binary and hexadecimal formats.
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