Certified Ethical Hacker (CEH v10) — Question 8

You are the Network Admin, and you get a complaint that some of the websites are no longer accessible. You try to ping the servers and find them to be reachable. Then you type the IP address and then you try on the browser, and find it to be accessible. But they are not accessible when you try using the URL.
What may be the problem?

Answer options

• A. Traffic is Blocked on UDP Port 53
• B. Traffic is Blocked on TCP Port 80
• C. Traffic is Blocked on TCP Port 54
• D. Traffic is Blocked on UDP Port 80

Correct answer: A

Explanation

The correct answer is A because DNS queries, which use UDP Port 53, are necessary for resolving URLs to IP addresses. If traffic is blocked on this port, the URL cannot be resolved, leading to accessibility issues. Options B, C, and D do not relate to DNS resolution, as TCP Port 80 is for HTTP traffic and does not affect URL resolution.