DHCP (Dynamic Host Configuration Protocol)
IP
IP
address
IP
addressing
IP
addressing can be done by two ways :-
1.
Static (Manually)
2.
Dynamic (Automatically)
There
are different methods for dynamic IP addressing like DHCP, ICS, Proxy, NAT, RAS,
VPN, APIPA etc.
DHCP
DHCP is use for dynamic IP addressing and it can assign
IP address on the temporary basis, by default
8 days. DHCP server can be
configure on Member server and DC only, not on Standalone server. It is use to manage IP addressing. DHCP
server will not only assign IP address but also re-allocate the clients and
make complete configuration of TCP/IP.
DHCP is based on BOOTP (Boot Strap Protocol) and can be use in WAN, Internet and Intranet.
If client machine have 2 NICs, then it will be assign
two IP addresses.
Working of DHCP
Stage I -
Lease Process :-
Client machine will be start and broadcast its MAC
address in the entire network, then it will DISCOVER the DHCP server.
DHCP server will OFFER
the range of IP address to client machine.
Client machine will REQUEST for IP address from DHCP server.
DHCP server will send ACKNOWLEDGEMENT and assign IP address.
NOTE: Whenever client machine will be restart , then
IP address may change.
NOTE:
DHCP server must have Static IP addressing.
Stage II - Renewal Process :-
Client machine will automatically request to renew the
lease after 50 percent lease is over.
Client will again request after 87.5% , if not renew by
DHCP server, then again request after 100% lease is over. Then client machine will be out of network
(0.0.0.0) and within 5 minutes get IP address from APIPA (169.254.0.0)
APIPA (Automatic
Private IP Addressing)
APIPA is part of registry in all OS, it can be use
within LAN, it is slow and network ID is always 169.254.0.0
DHCP Relay Agent
It is service in router to find DHCP server of another
site. It is interface between users and the DHCP server of another subnet.
Designing
of DHCP
1. Centralize
DHCP It means we can use only one
DHCP server for the different sites, we have to use DHCP Relay Agent in the
branch offices.
2. Distributed
DHCP It means every branch office
will have their own DHCP servers.
3. Hybrid
DHCP It means some branch offices
have dedicated DHCP server and some branch offices are sharing single DHCP
server.
Options
in DHCP server
1. Authorize It means
DHCP server will be integrated with AD, then it can assign IP address.
2. Scope It means range or pool of IP
addresses for the client machines. We can create more than one scope in DHCP
server. First scope must have same network ID as DHCP server. All the scopes
must have different network ID.
3. Multicast scope This scope is use for multicasting purpose
only.
4. Superscope It is collection of the different
scopes of a DHCP server. It is use when we need more IP addresses than
previously planned.
5. Exclusion We can exclude some of the IP addresses
within a scope. DHCP server will not assign these IP address and can be use as
static IP address.
6. Reservation We can reserve IP address for particular
client machine like Print server. We need MAC address of that particular
client.
7. Address Pool This option will show existing scopes and
excluded IP address.
8. Address Lease This option will show client
information.
9. Scope Option
and Server Option These two
options are use for additional settings in the existing scopes of a DHCP
server. Scope Option is use for
particular scope while Server Option is use for all the scopes of a DHCP
server. Scope Option will have priority over Server Option in case of any
confliction.
To install and
configure DHCP server :-
Open Server Manager
-> Roles -> Add
Roles -> Select DHCP
To create scope and to authorize DHCP server :-
Program ->
Admin. tools -> DHCP
Client machine :-
RUN cmd ->
ipconfig
/release <┘
ipconfig
/renew <┘
or restart client machine
ipconfig
/all <┘
No comments:
Post a Comment