TryHackMe DNS in Detail

References

• Try Hack Me. (2021). DNS in Detail - How the web works [YouTube Video]. In YouTube. https://youtu.be/jpTY1S5vs9k

What is DNS?

What does DNS Stand for?

• According to the information provided in the question:

DNS (Domain Name System) provides a simple way for us to communicate with devices on the internet without remembering complex numbers.

Answer: Domain Name System

Domain Hierarchy

What is the maximum length of a subdomain?

• According to the information provided in the question:

A subdomain name has the same creation restrictions as a Second-Level Domain, being limited to 63 characters and can only use a-z 0-9 and hyphens (cannot start or end with hyphens or have consecutive hyphens).

Answer: 63

Which of the following characters cannot be used in a subdomain: 3, b, _ or -?

Answer: _

What is the maximum length of a domain name?

• According to the information provided in the question:

You can use multiple subdomains split with periods to create longer names, such as jupiter.servers.tryhackme.com. But the maximum length must be kept below 253 characters.

Answer: 253

What type of TLD is .co.uk?

• According to the information provided in the question:

There are two types of TLD, gTLD (Generic Top Level) and ccTLD (Country Code Top Level Domain).

Answer: ccTLD

Record Types

What type of record would be used to advise where to send email?

• According to the information provided in the question:

MX Record

These records resolve to the address of the servers that handle the email for the domain you are querying...

Answer: MX

What type of record handles IPv6 addresses?

• According to the information provided in the question:

AAAA Record

These records resolve to IPv6 addresses, for example 2606:4700:20::681a:be5

Answer: AAAA

Making A Request

What field specifies how long a DNS record should be cached for?

• According to the information provided in the question:

DNS records all come with a TTL (Time To Live) value. This value is a number represented in seconds that the response should be saved for locally until you have to look it up again.

Answer: TTL

What type of DNS Server is usually provided by your ISP?

• According to the information provided in the question:

A Recursive DNS Server is usually provided by your ISP, but you can also choose your own.

Answer: recursive

What type of server holds all the records for a domain?

• According to the information provided in the question:

An authoritative DNS server is the server that is responsible for storing the DNS records for a particular domain name and where any updates to your domain name DNS records would be made.

Answer: authoritative

Practical

What is the CNAME of shop.website.thm?

• Using the interactive terminal provided:

user@thm:~$ nslookup --type=CNAME shop.website.thm
Server: 127.0.0.53
Address: 127.0.0.53#53

Non-authoritative answer:
shop.website.thm canonical name = shops.myshopify.com

Answer: shops.myshopify.com

What is the value of the TXT record of website.thm?

• Using the interactive terminal provided:

user@thm:~$ nslookup --type=TXT website.thm
Server: 127.0.0.53
Address: 127.0.0.53#53

Non-authoritative answer:
website.thm text = "THM{7012BBA60997F35A9516C2E16D2944FF}"

Answer: THM{7012BBA60997F35A9516C2E16D2944FF}

What is the numerical priority value for the MX record?

• Using the interactive terminal provided:

user@thm:~$ nslookup --type=MX website.thm
Server: 127.0.0.53
Address: 127.0.0.53#53

Non-authoritative answer:
website.thm mail exchanger = 30 alt4.aspmx.l.google.com

Answer: 30

What is the IP address for the A record of www.website.thm?

• Using the interactive terminal provided:

user@thm:~$ nslookup --type=A website.thm
Server: 127.0.0.53
Address: 127.0.0.53#53

Non-authoritative answer:
Name: website.thm
Address: 10.10.10.10

Answer: 10.10.10.10