If you're planning on taking the Security+ exam or Network+ exam, you should have a basic understanding of DNS servers.
For example, can you answer this question?
Q. You need to reboot your DNS server. Of the following choices, which type of server are you MOST likely to reboot?
A. Unix server
B. Apache server
C. BIND server
D. Web server
More, do you know why the correct answer is correct and the incorrect answers are incorrect?
