DHCP

• Purpose is to allocate ip address to Machines connected over the network

DNS Servers

• Reference
• Resolving name with ip address is major responsibility of DNS Servers.
• DNS Servers are generally used for
  • Internal DNS Servers: These servers are maintained in your organization for internal name resolutions
  • Public DNS Servers: These servers are maintained by some organizations for internet domain name resolutions
• Public DNS Servers Usecase:
  • We are running our application on AWS/Azure.
  • When we run in cloud we get public ip address.
  • To all external users, we expose applications by giving domain names
  • To get domain names, you purchase them from domain sellers (Go-daddy, hostinger.in)
  • We have to make Public DNs servers aware of our ip address

DNS Name Resolution

1. Whenever you make a request, first name to ip resolution is checked in local hosts file (C:\Windows\System32\drivers\etc\hosts in Windows & /etc/hosts in *nix )
2. The request will be made to root servers. Root servers respond with TLD server
3. Request to TLD ns will result in ns
4. NS will have a file called as Zone file which has records

Record Types

• A or AAAA: Name to IP
• CNAME: Alias record
• PTR Record: inverse of A or AAAA
• MX Records: Mail exchange servers
• SOA:
• CAA