Description: The subnet mask separates particular portions of an IP address. Subnet mask is usually used by the network software or hardware. It is a routing prefix which is expressed in a particular notation.
Description: Constant subnetting practice is the only way to pass your CCNA! This site automatically generates questions on subnetting using a random number generator.
Description: Subnetting practice questions, tutorials, and a competitive game to help you master IP networking. Additionally, we have hundreds of free CCNA Practice Questions with summaries and answer feedback.
Description: The most extensive subnetting practice site on the Internet. The best place to practice for your networking career and the CCNA, Network+, etc.