What is DHCP:-

• It gives Addresses automatically to the client who is requesting for an IP address

• Centralized IP Address management

• DHCP prevent IP address conflict and help conserve the use of client IP Address on the on the network

• DHCP reduces the complexity and amount of administrator work by assigning TCP/IP configuration automatically to the clients.

Types of IP Addresses:-

• Static IP address

                  - Address that are manually assigned and do not change over time

• Dynamic IP address

                 - Address that are automatically assigned for a specific period of time and might change
Authorization:-

• In domain model the DHCP server should be authorized to assign the IP addresses to client.

• It is a security precaution that ensures that only authorized DHCP server can run in the network. To avoid computer running illegal DHCP server in the network.

Scope:-

• A scope is a range of IP addresses that are available to be leases to clients.

DHCP Lease Generation Process(DORA):-

• This process of assigning the IP addresses by the DHCP server also known as DORA (Discover, Offer, Request, and Acknowledgement).

1. Step 1:

                    Your computer sends a "Discovery" request, asking for it's IP information from
                     any listening DHCP servers.
     2. Step 2:
                     Any listening DHCP servers will "Offer" their configuration information to your
                     workstation.
     3. Step 3:
                    You workstation chooses the best lease then "Requests" that lease from the
                     corresponding DHCP server.
    4. Step 4:
                    The DHCP server you requested the IP configuration information from then
                    "Acknowledges" your request and leases you the IP configuration information.

What is DHCP Reservation? :-

• A reservation is a specific IP address, within a scope that is permantly reserved to a specific DHCP client

What is DHCP options? :-

• DHCP Scope options are other server addresses given to client along with IP Configuration.

Posted by ashwaq javed at 7:42 AM No comments:

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Labels: Windows Administration

Read-Only Domain Controllers (RODC)

Read-Only Domain Controllers (RODC):-

• RODC address some of the problems that are commonly found in branch offices.

• These locations might not have a DC, Or they might have a writable DC but no physical security to that DC, low network bandwidth, or inadequate expertise to support that DC.

Functionality of RODCs:-

• Read-Only DC database

• Uni-directional replication

• Credential caching

• Administrator role separation

Read-only AD DS Database:-

• Except for accounts password, an RODC holds all the Active Directory objects and attributes that a writable domain controller holds.

• However, changes cannot be made to the database that is stored on the RODC. Changes must be made on a writable domain controller and then replicated back to the RODC.

Uni-Directional Replication:-

• Because no changes are written directly to the RODC, no changes originate at the RODC. Accordingly, writable DCs do not have to pull changes from the RODC. This means that any changes or corruption that a malicious user might make at branch locations cannot replicate from the RODC to the rest of the forest.

Credential Caching:-

• By default, an RODC does not store any user credentials.

• You must explicitly allow any credential to be cached on a RODC.

Administrator Role Separation:-

• You can delegate local administrative permissions for an RODC to any domain user without granting that user right for the domain or other domain controllers.

• In this way, the branch user can be delegated the ability to effectively manage and perform maintenance work on the server, such as upgrading a driver in the branch office RODC only, without compromising security of the rest of the domain