11) DNS & DHCP

 DNS, DHCP

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• DNS 

     DNS stands for Domain Name System. It is a service that translates the domain name into IP addresses. DNS is a directory service that provides a mapping between host on the network.

• Default service port no. for DNS: 

1. TCP-53 (Transfer) 
2. UDP-53 (Quarries) 

• Default location → C: \ windows \ system32 \ DNS

• DHCP

     DHCP stand for Dynamic Host Configuration Protocol. It is a service or server that provided IP configuration. Like: IP Address, Subnet mask, Gateway, and DNS Address to client device automatically. 

• DHCP server is known as DORA process.

               D → Discover
               O → Offer
               R → Request 
               A → Acknowledgement

• Leased duration 

            For Wired Network (default) → 8 days 
            For Wireless Network (default) → 8 hour 

• Leased renewal time process 

              T1 → 50% of leased duration
              T2 → 67.5% of leased duration

• Service port no. 

               For Server → UDP 67
               For Client → UDP 68

• DHCP option 

                 Subnet mask → 001
                 Router → 003
                 DNS server → 006
                 DNS Domain name → 015
                 Perform router discovery → 031
                 Static route → 033
                 Vendor-specific information → 043
                WINS / NBNS server → 044
                WINS / NetBT node type → 046
                Net BIOS scope ID → 047
                Lease time → 051
                Renewal (T1) time value → 058
                Rebinding (T2) time value → 059
                Classless static routes → 249

• Default location of DHCP database         C: \ windows \ system32 \ DHCP

• Cammand 

                ipconfig 

                ipconfigɸ/all 

                ipconfigɸ/renew 

                ipconfigɸ/release 

                ipconfigɸ/flashdns 

•  DHCP Relay Agent 

     DHCP Relay Agent is a protocol that works between DHCP Client and DHCP Server located on different segment or different network. 

• DHCP Configuration 

  1) Open Server Manager 

 2) Go Manage and open Add Roles and Feature

 3)  click Next ......... Next ......... Next

 4)  click Next 

 5)  ☑ Restart the destination server automatically if required

 6) After installing click on Close

 7) Open Tools in server manager 

 8) Click DHCP 

 9) Open New Scope

 10) click Next

 11) click Next

 12) Set IP Range

 13) click Next

 14) Set Static IP

 

 15) click Next

16) click Next

 

17) click Next

17) click Finish