(N4) Servers and Services – part4 – DHCP and DNS
20220902 124514
DHCP – Dynamic Host Configuration Protocol
•Port No: 67,68
•DHCP server assigns ip address to clients automatically
•Assigning ip address – Manual , Automatic
•Manual – Static
•User manually configure ip address to Computer, and the ip address never changes with change of network also.
•More no. of device increase , it difficult assign ip address
•Possible wrong addresses, conflict (same ip assigned to more than one )
•Not everyone knows how to assign ip address
•Can’t assign for some devices – printers, mobile phones, smart tv, smart led, ..
•Automatic – Dynamic
•Use dhcp server to Assign ip address to client, ip address changes frequently
•When we change network ip address also changes automatically
•Less/no possibility of entering wrong addresses , conflicts
•Everyone not required to know how to assign ip address
•DHCP server gives/assign ip address to different type of devices ex. Printers, smart tv, smart led, mobile,..also
•APIPA address: Automatic Private IP address – 169.254.x.x
•If system is unable to get ip address from dhcp server, system assign an ip address itself from APIPA Range(169.254.0.1-169.254.255.254)
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•When you change network , ip address changes according connected network, if it not changes?then
•Check your system/pc configure ip address manually or what
•System got ip address as 169.254.x.x..
•check dhcp server
•Make sure dhcp server runs fine
•
•Run – ncpa.cpl – rt on nic – disable – enable
•CMD:
•ipconfig /release — remove old ip address
•Ipconfig /renew — gets new ip address from dhcp server
•DNS – Domain Name System
•Port No: 53
•Maps Name to IP address
•Open browser – www.google.com, We need ip address of www.google.com. Our PC send request to DNS server and asks ip address of www.google.com. DNS Server returns ip address of www.google.com, now we can reach to www.google.com server with ip address.
•* all communication with ip address only
•Mobile phone contact list – example for DNS server / DNS records
•Contact List – Name and Phone No
•When you call to Some one –open name & call, but call goes with Phone No.
•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
by Latif Shaik
linux dhcp client
