(HVA1) Day3 Servers and Services part4 DNS Server
20240612 143923
DNS: Domain Name System
Port No. 53
DNS Server:
Contains records of device or services which is a map of the device name in a domain to the ip address.
Maps Name to IP Address
Resolves Name to IP Address
Note: All communication by IP Address only
•DNS – Domain Name System
•Port No: 53
•Maps Name to IP address.
If you try to communicate with the name of the host(servers) and you don’t know the ip address of the host, your system sends a request to the DNS Server to get the ip address of that host. Then DNS Server returns ip address of the host(in domain)
•Open browser – www.google.com, We need the ip address of www.google.com. Our PC sends a request to the DNS server and asks for the ip address of www.google.com. DNS Server returns the ip address of www.google.com, now we can reach to www.google.com server with ip address.
•Mobile phone contact list – example for DNS server / DNS records
•Contact List – Name and Phone No
•When you call someone –open name & call, but call goes with Phone No.
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ping www.google.com
Pinging www.google.com [142.250.193.100] with 32 bytes of data:
Reply from 142.250.193.100: bytes=32 time=16ms TTL=119
Reply from 142.250.193.100: bytes=32 time=17ms TTL=119
Reply from 142.250.193.100: bytes=32 time=16ms TTL=119
Reply from 142.250.193.100: bytes=32 time=18ms TTL=119
Ping statistics for 142.250.193.100:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 16ms, Maximum = 18ms, Average = 16ms
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•NetBIOS – Computer Name to IPv4 Address
•LLMNR – Computer Name to IPv6 Address
•WINS – Windows Internet Naming Service•WINS is like DNS – Naming Service – name servers
•WINS works in Windows but not work with other OSs
•WINs supports NetBIOS and IPv4 only, Not support FQDN and IPv6
•FQDN- Fully Qualified Domain Name
•Fqdn is combination of hostname and domain name (subdomains also)
•Domain Name : Contoso.com
•Host Name: Server1
•FQDN: Server1.Contoso.com
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ipv4
