Alan Freedman -- The Computer Language Company - Computer Desktop Encyclopedia
Computer Desktop Encyclopedia
Longest-Running Tech Reference on the Planet

A CDE Definition

You'll love The Computer Desktop Encyclopedia (CDE) for Tech Term of the Day (TTOD)


wildcard mask

A coding system used with access control lists to identify IP addresses. A line entry in the list contains a command, an IP address and a mask that references the IP address. Although access list commands are cryptic, an English translation of a line entry might be "deny entry to packets with these addresses."

The mask is a binary pattern that contains the same number of bits as the IP address. Each 0 bit in the mask means that the corresponding bit in the IP address must match exactly. A 1 indicates that the bit does not have to match and can be ignored. For example, in order to stipulate a specific IP address, that address would be accompanied by a wildcard mask of To refer to all packets with Class A addresses in the 10.10.x.x range, the wildcard mask would be

The Opposite of the Subnet Mask
Whereas a 0 bit in a wildcard mask means "match the bits," a 0 in a subnet mask means "do not match." Thus, a wildcard mask of is the equivalent of a subnet mask of See access control list, subnet mask and IP address. See also wild cards.

Personal Use Only

Before/After Your Search Term
WikiWikiWebWilliams tube
wild cardWiMAX 2
wild cardsWiMAX Forum
Wild Wooly WebWiMedia
wildcardWiMedia Alliance

Terms By Topic
Click any of the following categories for a list of fundamental terms.
Computer Words You Gotta KnowSystem design
Job categoriesUnix/Linux
Interesting stuffPersonal computers
InternetIndustrial Automation/Process Control
Communications & networkingAssociations/Standards organizations
HistoryDesktop publishing
ProgrammingHealthcare IT
System design