Free defensive cyber tools
IPv4 CIDR and Subnet Calculator
Plan and verify IPv4 networks with immediate CIDR calculations and copyable addressing results.
- Calculate network and broadcast addresses for prefixes from /0 through /32.
- Display subnet masks, wildcard masks, first and last usable hosts.
- Identify private address space and total versus usable capacity.
SurfaceVector cybersecurity tools
Authoritative cybersecurity sources
SurfaceVector connects defensive workflows with resources from CISA, the CVE Program, FIRST, NIST, and DISA STIGs.