Wildcard Calculator

Instantly perform complex bitwise subnetwork calculations. Invaluable for writing on-the-fly Cisco OSPF statements or Extended ACLs.

IP Address

CIDR

Subnet Math Shortcuts:

Wildcard Mask: The literal mathematical inverse of a Subnet Mask (255.255.255.255 - Subnet Mask).
OSPF: network 10.0.0.0 0.0.0.255 area 0
EIGRP: Also strictly requires Wildcard masks.
ACLs: Requires Wildcard masks to identify host blocks.

Network Derivations

Waiting for IP & CIDR variables...