Open Source Room: Microsoft-Windows-Server-2019-(DHCP Server)

DHCP Server

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A DHCP Server is a network server that automatically provides and assigns IP addresses, default gateways and other network parameters to client devices. DHCP is an service that provides TCP/IP settings, such as IP address, subnet mask, default gateway and DNS server to the client automatically.
DHCP services exist for networks running Internet Protocol version 4 (IPv4), as well as version 6 (IPv6). The IPv6 version of the DHCP protocol is commonly called DHCPv6.
The Reverse Address Resolution Protocol (RARP) was defined in RFC 903 in 1984 for the configuration of simple devices, such as diskless workstations, with a suitable IP address.
RARP was superseded by the Bootstrap Protocol (BOOTP) defined in RFC 951 in September 1985.
DHCP was first defined in RFC 1531 in October 1993, but due to errors in the editorial process was almost immediately reissued as RFC 1541.
DHCPv6 was initially described by RFC 3315 in 2003. After updates by many subsequent RFCs.
DHCP is an IETF standard based on BOOTP protocol.
A device that gets TCP/IP configuration using DHCP protocol is known as DHCP client, device which provides TCP/IP configuration is known as DHCP Server.

Address Allocation Process of DHCP:

DHCP Message Type:

- DHCP Discover Message

- DHCP Offer Message

- DHCP Request Message

- DHCP ACK Message

- DHCP Nak Message

- DHCP Decline Message

- DHCP Release Message

- DHCP Inform Message

DHCP Nak Message:-

If the IPv4 address requested by the DHCP client cannot be used (another device may be using this IPv4 address), the DHCP server responds with a DHCPNak (Negative Acknowledgment) packet. After this, the client must begin the DHCP lease process again.

DHCP Decline Message:-

A DHCP decline message is sent by a DHCP client to notify the DHCP server that the allocated IP address conflicts with another IP address. The DHCP client then applies to the DHCP server for another IP address.

DHCP Release Message:-

A DHCP release message is sent by a DHCP client to release its IP address. After receiving a DHCP release message, the DHCP server can allocate this IP address to another DHCP client.

DHCP Inform Message

DHCP Inform message is sent by DHCP client to obtain other network configuration parameters such as gateway address and DNS server address after the DHCP client has obtain an IP address.

DHCP Discover Message

DHCP client sends a DHCP Discover broadcast on the network for finding a DHCP server. If there is no respond from a DHCP server, the client assigns itself an Automatic Private IPv4 address (APIPA).

DHCP Offer Message

DHCP servers on a network that receive a DHCP Discover message respond with a DHCP Offer message, which offers the client an IPv4 address lease.

DHCP Request Message

Clients accept the first offer received by broadcasting a DHCP Request message for the offered IPv4 address.

DHCP Acknowledgment Message

The server accepts the request by sending the client a DHCP Acknowledgment message.

DHCP Terminologies:

- DHCP Server

- DHCP Client

- DHCP Scope

- Super Scope

- DHCP Lease

- DHCP Reservation

- Exclusion Range

DHCP Server Authorization:-

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After installing the DHCP roles on Windows Server 2019, one of the first actions that will need to be completed is to authorize the server in the Active Directory infrastructure. This action is essential so that the DHCP server can distribute IP address to Active Directory clients.

Practical-1) Installation the rolls of DHCP.

Select a server from the server pool.

Select "Add Features"

Select "Restart" button & click on "OK".

Practical-2) Configuration of DHCP server & create a scope.

Go to the "DHCP Manager" via "Tools --> DHCP".

Expand domain and Right Click on IPv4 --> Select New Scope.

Click on the "Next" button.

Give the name of scope "Manufacturing_Department".

Assign the "Start & End IP Address with Length & Subnet Mask".

If you use some IP in reservation now you can use "Exclusions and Delay".

Select Lease Duration. (By default 8 days set already)

Click on "Yes" button.

Give the IP address of Default Gateway for DHCP client.

Give the server name & select add button.

Again give the server name & click Add button for add WINS server.

Click on the "Yes" button.

Click on Finish button.

Right click on domain_(server2019.act.local)--> Select "All Task" --> Restart.

Now go to the DHCP client. Use this command in command prompt.

1) ipconfig /release

2) ipconfig /renew

You can see the TCP/IP configuration that is assigned by DHCP server. IP address 192.168.10.21 available on DHCP client. You can see client details on DHCP server also in Address Lease option of IPv4.

Practical-3) DHCP Reservation configuration.

By the help of DHCP reservation you can fix the ip address to a particular computer machine.

Right click on Reservations --> New Reservation --> Type the MAC address of destination computer machine & assign the IP address from pool --> Select both option --> Click on OK button.