What may be the problem?

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?
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

View Answer

Answer: A

Explanation:

Most likely have an issue with DNS.

DNS stands for “Domain Name System.” It’s a system that lets you connect to websites by matching human-readable domain names (like example.com) with the server’s unique ID where a website is stored.

Think of the DNS system as the internet’s phonebook. It lists domain names with their corresponding identifiers called IP addresses, instead of listing people’s names with their

phone numbers. When a user enters a domain name like wpbeginner.com on their device, it looks up the IP address and connects them to the physical location where that website is stored.

NOTE: Often DNS lookup information will be cached locally inside the querying computer or remotely in the DNS infrastructure. There are typically 8 steps in a DNS lookup. When DNS information is cached, steps are skipped from the DNS lookup process, making it quicker. The example below outlines all 8 steps when nothing is cached.

The 8 steps in a DNS lookup: