Dynamic Host Configuration Protocol

1. Microsoft Server 2008 R2 Dynamic Host Configuration Protocol

2. Dynamic Host Configuration Protocol • MAC Address • IP Addressing • DHCP Client • DHCP Server • Scope • Exclusion Range • Reservations • Netsh

3. HISTORY OF DHCP

4. THE ROLE OF DHCP • Dynamically assigns TCP/IP addresses • Dynamically assigns TCP/IP configuration information • Simplifies network administration

5. M a n u a l T C P / I P C o n f i g u r a t i o n A u t o m a t i c T C P / I P C o n f i g u r a t i o n M a n u a l T C P / I P C o n f i g u r a t i o n A u t o m a t i c T C P / I P C o n f i g u r a t i o n IP addresses entered manually IP addresses are supplied auto- on each client computer matically to client computers Possibility of entering incorrect Ensures that client always uses or invalid IP address correct configuration information Incorrect configuration can Client configuration updated lead to communication automatically to reflect network and network issues changes Administrative overload on Elimination of source of network networks on which computers problems are frequently moved DYNAMIC VERSUS MANUAL TCP/IP ADDRESS ASSIGNMENT

6. Ethernet Address and IP address • Each machine has an Ethernet address and IP address • Ethernet is a unique 48 bit address • Also known as MAC (media access control) addresses

7. Ethernet Address and IP Address • Can also view the MAC address by typing: • C:\>ipconfig /all • Start->run->msinfo32 <enter>

8. IP Addressing Rules and Concepts • Addresses you cannot assign • Default route address: 0.0.0.0 • Loopback address: 127.0.0.1 • Network number: 172.17.13.0 • IP Broadcast address: 172.17.13.255

9. Dynamic Host Configuration Protocol • Used for manageability and automation of IP address assignment on networks. • Ie. ISP’s use DHCP when you establish connection.

10. Scopes and Superscopes • When configuring DHCP, the first step is to create a range of addresses that will be managed. This is called a scope. • A single DHCP server can service more than one subnet by assigning a scope to each subnet. • You can create a superscope to service more than on range of IP’s on the same segment.

11. D H C P M e s s a g e T y p e D e s c r i p t i o n D H C P M e s s a g e T y p e D e s c r i p t i o n DHCPDISCOVER Used by clients to request configuration parameters from a DHCP server DHCPOFFER Used by servers to offer IP addresses to requesting clients DHCPREQUEST Used by clients to accept or renew IP address assignment and to decline unaccepted servers DHCPDECLINE Used by clients to reject an offered IP address DHCPACK Used by servers to acknowledge a client’s acceptance of an offered IP address DHCPNACK Used by servers to reject a client’s acceptance of an offered IP address DHCPRELEASE Used by clients to terminate an IP address lease DHCPINFORM Used by clients to obtain additional TCP/IP addresses DHCP MESSAGE TYPES

12. THE INITIAL DHCP LEASE PROCESS

13. DHCP LEASE RENEWAL PROCESS

14. WHAT IS A DHCP RELAY AGENT?

15. Leases, client options exclusions and reservations • A lease determines how long the client will maintain the same IP address before it is issued a new lease of another IP address • Client options are configured during the setup or after. They can range from simply setting the default gateway, DNS and WINS servers to Network Time Servers and NetBios Settings • Exclusions are IP Addresses within the scope that you do not want assigned dynamically. For instance you may statically assign your server’s IP address and do not want that assigned to another machine. What would happen if it did assign it’s own IP address? • A single exclusion can be created or a range of exclusions • Reservations ensure that the same MAC gets the same ip address every time. Reservations are created within the scope.

16. DHCP Management Console

17. WHAT IS A DHCP SCOPE?

18. WHAT IS A DHCP SCOPE?

19. WHAT ARE DHCP CLIENT RESERVATIONS? Client reservations permanently reserve a specific address for a specific client.

20. Manually Renewing/Releasing

21. Questions