IP Addressing and Subnetting
Calculated locally
Wildcard Mask Calculator
Convert CIDR or subnet masks into wildcard masks with binary comparisons and Cisco-style examples.
Learn before you deploy
Reference PacketToolbox learning content related to this workflow.
Tool input
Use the fields below and run the calculation or generation locally.
Results
Review output and validation notes before production use.
How it works
Use a CIDR or contiguous mask to derive wildcard masks for ACL and OSPF statements.
All processing runs in-browser with no external API dependency.
Practical example
Example: /24 returns wildcard 0.0.0.255.
Related tools
Use these together for complete design and troubleshooting workflows.
- IPv4 Subnet Calculator for subnet boundary and wildcard checks.
- VLSM Planner for hierarchical IPv4 allocation.
- Route Summarization Calculator for clean route advertisement planning.
- Cisco ACL Builder for policy-generation workflows.