My Second Cybersecurity Blog Post: DNS, Caching, and TryHackMe Practical Tasks

Today I continued my learning journey on TryHackMe by diving into the topic of DNS (Domain Name System). I focused on how DNS works, how caching impacts performance, and how different DNS records are used in practice.

Some of the key concepts I explored:

• Recursive DNS vs. Local Cache
  I learned that DNS queries often go through recursive servers which store the results temporarily. This helps reduce load and improve speed. My own device can also store DNS records in a local cache, but only for a limited time. After that, the data is discarded to save memory.

• Types of DNS Records
  I experimented with several record types using the TryHackMe virtual environment. For example, I used nslookup to retrieve:

  • CNAME records to find alias names for domains

  • TXT records which may include verification data

  • MX records for mail server info (including priority value)

  • A records that provide the IP address for a domain

• Hands-on Practice Using TryHackMe
  I completed a practical DNS task directly inside TryHackMe’s built-in terminal and web interface. This was helpful because I initially tried running the commands on my local Windows machine, but it didn’t work - turns out the domain shop.website.thm is only recognized within TryHackMe’s simulated environment. That’s why my CMD terminal showed a ‘Non-existent domain’ error when I tried it locally.

You can see from the screenshot that the TryHackMe environment allowed me to simulate DNS queries successfully, something that wouldn’t be possible with normal Internet DNS due to the custom DNS environment in TryHackMe.

I answered quiz questions based on my findings and got everything right, including the priority value for the MX record and the IP for the A record. Definitely a confidence boost.

Tomorrow I’ll keep going. So far, I’m still focused on the Pre-Security path, but it’s already giving me a good mix of theory and hands-on.