DHCP Managed Configuration of TCP/IP Hosts Purpose of DHCPPurpose of DHCPFrom RFC2131: From RFC2131: The Dynamic Host The Dynamic Host Configuration Protocol (DHCP) provides a Configuration Protocol (DHCP) provides a framework for passing configuration information framework for passing configuration information to hosts on a TCP/IP networkDHCP consists to hosts on a TCP/IP networkDHCP consists of two components! a protocol for delivering of two components! a protocol for delivering host"specific configuration parameters from a host"specific configuration parameters from a DHCP server to a host and a mechanism for DHCP server to a host and a mechanism for allocation of network addresses to hostsallocation of network addresses to hosts DHCP functional goalsDHCP functional goals !ost "it!out a #alid IP address locates and !ost "it!out a #alid IP address locates and communicates "it! a DHCP ser#ercommunicates "it! a DHCP ser#er DHCP ser#er passes configuration DHCP ser#er passes configuration parameters$ including an IP address$ to t!e parameters$ including an IP address$ to t!e !ost!ostT!e DHCP ser#er ma% d%namicall% allocate T!e DHCP ser#er ma% d%namicall% allocate addresses to !osts and reuse addressesaddresses to !osts and reuse addressesHosts can detect "!en t!e% re&uire a ne" IP Hosts can detect "!en t!e% re&uire a ne" IP addressaddress'na#aila(ilit% of DHCP ser#er !as minimal 'na#aila(ilit% of DHCP ser#er !as minimal effect on operation of !ostseffect on operation of !osts )!at can %ou do "it! DHCP)!at can %ou do "it! DHCPPlug*and*pla%Plug*and*pla%Mo#e des+top PCs (et"een officesMo#e des+top PCs (et"een offices,t!er restructuring * c!ange su(net ,t!er restructuring * c!ange su(net mas+smas+sMo(ile IP * laptopsMo(ile IP * laptopsMo#ing e&uipment * carta(leMo#ing e&uipment * carta(le )!at DHCP )!at DHCP doesn#tdoesn#t dodo-upport multiple addresses per interface-upport multiple addresses per interfaceInform running !ost t!at parameters !a#e Inform running !ost t!at parameters !a#e c!angedc!anged-upport inter*ser#er communication-upport inter*ser#er communicationPro#ide aut!enticated message deli#er%Pro#ide aut!enticated message deli#er% )!at DHCP )!at DHCP doesn#tdoesn#t dodoConfigure routers and ot!er net"or+ Configure routers and ot!er net"or+ e&uipmente&uipmentDesign net"or+ addressing planDesign net"or+ addressing planDetermine ot!er configuration parametersDetermine ot!er configuration parameters.ocate ot!er ser#ers.ocate ot!er ser#ers DHCPDHCP,#er#ie",#er#ie" D%namic Host Configuration Protocol D%namic Host Configuration Protocol Centrali/ed distri(ution and management Centrali/ed distri(ution and management0 Clients o(tains IP addresses from t!e ser#er Clients o(tains IP addresses from t!e ser#er0 utomates TCP/IP configuration utomates TCP/IP configuration0 dministrators don1t !a#e to manuall% configure eac! client dministrators don1t !a#e to manuall% configure eac! client0 Centrali/es IP address management Centrali/es IP address management0 TCP/IP propert% c!anges are configured at t!e DHCP ser#er TCP/IP propert% c!anges are configured at t!e DHCP ser#er DHCP ,perationDHCP ,perationDCHP DI-C,23R DCHP DI-C,23RDCHP ,FF3R DCHP ,FF3R DHCP ,perationDHCP ,perationDCHP R34'3-T DCHP R34'3-Tt t!is time$ t!e DHCP clientt t!is time$ t!e DHCP client can start to use t!e IP address can start to use t!e IP addressRene"ing a .ease Rene"ing a .ease5sent "!en 678 of lease !as5sent "!en 678 of lease !as e9pired: e9pired:If DHCP ser#er sendsIf DHCP ser#er sends DHCP;C