#Network

Domain Name System

To have a mail server you should have a DNS server first.

Friendly version of IP addresses.

E.g.: 142.250.178.131 : Ip address of Google Search 8.8.8.8 is the public DNS of Google

We don't save all the domains in one list, they are categorized. like .com .fr .eu .gouv.fr

DNS tree makes the categorization for easier finding of domains.

![[Pasted image 20240227095821.png]]

Difference between URL and domain, URL includes the domain name too:

![[Pasted image 20240227095941.png]]

CMD on Windows:

ipconfig /all ipconfig -h : to see help / details we can see all the commands ifconfig on Linux

to see all the details of IP

tracert traceroute for linux

![[Pasted image 20240227101611.png]]

ping to see connectivity

nslookup to see ip address of a domain or vice versa

How does DNS work really ?

![[Pasted image 20240328102823.png]]