DHCP

Describe the lease process of the DHCP server?

DHCP Server leases the IP addresses to the clients as follows:

DORA

D (Discover): DHCP Client sends broadcast packets to identify the DHCP server; this packet will contain the source MAC.

O (Offer): Once the packet is received by the DHCP server, the server will send the packet containing Source IP and Source MAC.

R (Request): Client will now contact the DHCP server directly and request for the IP address.

A (Acknowledge): DHCP server will send an acknowledge packet which contains the IP address.

What is the DHCP Relay agent?

If you have routers separating some of your DHCP clients from the DHCP server you may have problems if they are not RFC compliant. This can be solved by placing a

DHCP relay agent on the local network area which is not actually a DHCP server which communicates on behalf of the DHCP Server. (The Relay agent component is live on windows 2003 Routing and Remote Access tool)

Why we want to use the conflict detection attempt our network?

Configure the DHCP server conflict detection attempts to 1

Explanation: when conflict detection attempts are set, the DHCP server uses the Packet Internet Groper (PING) process to test available scope IP addresses before including these addresses in DHCP lease offers to clients. A successful ping means the IP address is in use on the network. This results in the DHCP server not offering

To lease the address to A client.

If the ping request fails and times out, it indicates that the IP address is not in use on the network. In this case, the DHCP server offers to lease the address to a client. Each additional conflict detection attempt delays the DHCP server response by a second while for the ping request to time our. This in turn increases the load on the server. A value of no greater than two (2) is recommended for ping attempts

What is difference between scope and server options?

DHCP will manage multiple scope, each scope have different set of IP address and subnet and DNS and Gateway. If we want to supply unique DNS or WINS in our Network we can use Server Option the settings will be deploy all scope. If the scope does not require these settings, scope can use their own settings.  If conflict occurs then scope settings will be take presidency.