History

DHCP was first defined as a standards track protocol in RFC 1531 in October 1993, as an extension to the Bootstrap Protocol (BOOTP). The motivation for extending BOOTP was that BOOTP required manual intervention to add configuration information for each client, and did not provide a mechanism for reclaiming disused IP addresses.

DHCP• DHCP (Dynamic Host Configuration Protocol)

• it is a protocol used to dynamically assign IP address to hosts.

• DHCP makes it possible for you to access the internet using wireless hotspots at airport or coffee shops

• It enables clients on a network to obtain IP address and other information from a DHCP server.(DNS,Gateway,Net mask,…)

DHCP

• DHCP works on Application layer of Internet Protocol Suits.

• It uses UDP (Connectionless) to exchange IP and Messages to get and release IP address.

• Client for sending IP request to Server it uses UDP port 67 and for recievieng request from Server it uses UDP port 68.

Exchanging Messages

DHCP Packet

Operational code hardware type hardware length hop count Transaction ID

Number of second F UnusedClient IP addressYour IP address

Server IP addressGateway IP address

Client hardware address (16 bytes)Server name (64 bytes)

Boot file name (128 bytes)Options (Variable Length)

Security

The base DHCP protocol does not include any mechanism for authentication. Because of this, it is vulnerable to a variety of attacks.

These attacks fall into three main categories:– Unauthorized DHCP servers providing false

information to clients.– Unauthorized clients gaining access to resources.– Resource exhaustion attacks from malicious DHCP

clients.

Advantages & Disadvantages

Adv:-Safe and reliable configuration.-Reduced network administration.

Disadv:-Increases network traffic (uses broad case to find DHCP server)-Additional time to establish connections (because of time taken to get IP)

How to Install DHCP on a Windows Server 2008

How to Install DHCP on a Windows Server 2008

Configure a DHCP on a client

Configure a DHCP on a Client

Thanks .

questions?