Final answer:
A wildcard mask is the inverse of a subnet mask and is used to specify which parts of an IP address must be matched exactly in networking tasks. To find the wildcard mask for a given netmask, simply invert the bits of the netmask.
Step-by-step explanation:
The concept of wildcard masks is often used in networking, specifically when working with access control lists (ACLs) in Cisco routers or to determine what IPs are allowed in a given network. A wildcard mask is a string of bits that indicates which parts of an IP address should be matched exactly, and which parts can vary. This mask is the inverse of a subnet mask, where binary 0 in a subnet mask is represented as a binary 1 in a wildcard mask and vice versa. So, to determine the wildcard mask for a network address with a specific netmask, you would simply invert the subnet mask. For example, if the subnet mask is 255.255.255.0, the corresponding wildcard mask would be 0.0.0.255.