Networking is exciting, and the more I learn about networking the more I realize it's a profession that requires a lot of training and studying to become really skilled in.
While I was studying for the CCNA I created this simple tool to help me drill binary conversions.
How it works
The prefix2netmask app is a certification preparation tool to help students get exposure and training in binary conversion from a CIDR prefix to a subnet mask, or from a subnet mask to a CIDR prefix.
To submit an answer the student can press the enter key, or press the "Check!" button.
If the answer is correct a new task will be presented and the input field will be cleared. If the answer was incorrect the input field will glow red, and the student can retry. A new task will only be presented if a correct answer is provided.
Under the input field is a scoreboard. This will show how many correct answers were given compared to how many answers have been given.
There are three difficulty levels for each conversion. One for each network class.
- Level 1 will only provide Class C subnet masks
- Level 2 will only provide Class B subnet masks
- Level 3 will only provide Class A subnet masks
- Random will provide subnet masks from all three levels
Changing difficulty will not reset the counters.
When "Prefix → network mask" is selected, the student will be presented with an IP address suffixed with CIDR prefix annotation. If this Class A IP address is presented as task:
The correct subnet mask and answer is: 255.255.0.0
When "Network mask → prefix" is selected, the student will be presented with an IP address and a subnet mask. If the following information is provided:
IP address: 220.127.116.11 Network mask: 255.255.255.240
The correct CIDR prefix and answer is: 28
Note: The forward-slash (/) should not be provided in the answers.
Read about my CCNA journey!
The CCNA was my very first IT certification. I learned a lot about networking and Cisco switches and routers, but it was also a great life lesson that shaped how I approach learning.