Transcript Dynamic Host Configuration Protocol

Dynamic Host Configuration Protocol
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MAC Address
IP Addressing
DHCP Client
DHCP Server
Scope
Exclusion Range
Reservations
Netsh
HISTORY OF DHCP
THE ROLE OF DHCP
• Dynamically assigns TCP/IP addresses
• Dynamically assigns TCP/IP configuration
information
• Simplifies network administration
DYNAMIC VERSUS MANUAL TCP/IP
ADDRESS ASSIGNMENT
Manual TCP/IP Configuration
A u t o m a t ic T C P / I P C o n f ig u r a t io n
IP addresses entered manually
on each client computer
IP addresses are supplied automatically to client computers
Possibility of entering incorrect
or invalid IP address
Ensures that client always uses
correct configuration information
Incorrect configuration can
lead to communication
and network issues
Client configuration updated
automatically to reflect network
changes
Administrative overload on
networks on which computers
are frequently moved
Elimination of source of network
problems
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
Ethernet Address and IP Address
• Can also view the MAC address by typing:
– C:\>ipconfig /all
– Start->run->msinfo32 <enter>
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
Dynamic Host Configuration Protocol
• Used for
manageability
and
automation of
IP address
assignment on
networks.
– Ie. ISP’s use
DHCP when
you establish
connection.
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.
DHCP MESSAGE TYPES
DHCP Message Type
DHCPDISCOVER
DHCPOFFER
DHCPREQUEST
DHCPDECLINE
DHCPACK
DHCPNACK
DHCPRELEASE
DHCPINFORM
Description
Used by clients to request configuration parameters
from a DHCP server
Used by servers to offer IP addresses to requesting
clients
Used by clients to accept or renew IP address
assignment and to decline unaccepted servers
Used by clients to reject an offered IP address
Used by servers to acknowledge a client’s
acceptance of an offered IP address
Used by servers to reject a client’s acceptance of an
offered IP address
Used by clients to terminate an IP address lease
Used by clients to obtain additional TCP/IP addresses
THE INITIAL DHCP LEASE PROCESS
DHCP LEASE RENEWAL PROCESS
WHAT IS A DHCP RELAY AGENT?
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.
DHCP Management Console
WHAT IS A DHCP SCOPE?
WHAT IS A DHCP SCOPE?
WHAT ARE DHCP CLIENT
RESERVATIONS?
Client reservations permanently reserve a
specific address for a specific client.
Manually Renewing/Releasing
IPCONFIG /RELEASE
Releases IP Address configuration and
lease
IPCONFIG /RENEW
Request to renew same IP address or new
IP Address
Questions