CCNA 2 - Capitulo 7

CCNA 2 - Capitulo 7

1. DYNAMIC HOST CONFIGURATION PROTOCOL (DHCPv4)

   • CISCO ROUTER AS A DHCPv4 CLIENT
     • SIMILAR MANNER TO CLIENT COMPUTERS
       • THE METHOD DEPENDS ON THE ISP
     • COMMAND CONFIGURATION EXAMAPLE
       • R1(CONFIG)#IP ADDRESS DHCP
   • DHCPV4 CONCEPTS
     • DHCPv4 OPERATION
       • CLIENT / SERVER MODE
       • STEPS TO OBATION A LEASE
         • DHCPDISCOVER
           • CLIENT START PROCESS USING DHCPDISCOVER WITH
             • OWN MAC ADDRESS
             • COMMUNICATE WITH SERVER USING LAYER 2 BROADCAST (FF:FF:FF:FF:FF:FF)
         • DHCPOFFER
           • SERVER
             • RESERVES AN AVAILABLE IPV4 TO THE CLIENT
             • CREATE ARP ENTRY MAC ADDRESS CLIENT AND LEASED IPV4
         • DHCPREQUEST
           • LEASE ORIGINATION
             • BROADCAST ABOUT ACCEPTED OFFER
             • BINDING ACCEPTANCE NOTICE TO THE SELECTED SERVER FOR PARAMETERS IT HAS OFFERED
               • AND IMPLICIT DECLINE TO ANY OTHER SERVER
           • LEASE RENEWAL
             • UNICAST
         • DHCPACKNOWLEDGMENT
           • ACKNOWLEGGMENT
       • STEPS TO RENEW A LEASE
         • 1- DHCP REQUEST
           • UNICAST
             • CLIENT SENDS DIRECLY DHCP SERVER
           • BEFORE LEASE EXPIRES
           • DHCPACK IS NOT RECEIVED ?
             • BROADCASTS ANOTHER
         • 2 - DHCP ACKNOWLEDGMENT (ACK)
           • SERVER VERIFIES THE LEASE BY RETURNING
             • DHCPACK
         • WHATS YOUR PURPOSE ?
           • PRIOR TO LEASE EXPIRATION
         • RFC 2131
     • UDP
       • 67 CLIENT
       • 68 SERVER
     • DHCP SERVER
       • EASY MANAGE ; SCALABLE
       • DYNAMICALLY ASSIGNS OR LEASES POoL OF ADDESS
         • PERIOD OF TIME (LEASE TIME)
           • 24 HOURS
           • WEEK OR MORE
     • CLIENT DHCP
       • CLIENTS LEASE THE INFORMATION FROM THE SERVER DEFINED PERIOD

2. CONFIGURE A CISCO IOS DHCPv4 SERVER

   • CISCO IOS DHCPv4 SERVER
     • DISABLE CISCO IOS SERVER
       • GLOBAL MODE
         • R1(CONFIG)#NO SERVICE DHCP
       • DHCPv4 SERVER IS ENABLED BY DEFAULT
     • STEPS
       • 1.EXCLUDE IPV4 ADDRESS
         • R1(CONFIG)# IP DHCP EXCLUDED-ADDRESS low-address [high-address]
           • RANGE OR SINGLE ADDRESS
           • YOU CAN COMMAND MULTIPLE TIMES
         • ADDRESSES THAT ARE ASSIGNED TO ROUTERS , SWITCHES , SERVERS , PRINTERS ANS APs THEY SHOULD BE EXCLUDED.
       • 2. DEFINE A DHCPV4 POOL NAME
         • R1(CONFIG)# IP DHCP POOL VLAN-10
       • 3.CONFIGURE THE DHCPV4 POOL
         • ADDRESS POOL
           • R1(DHCP-CONFIG)#NETWORK NETWORK-NUMBER [MASK | / PREFIX-LENGTH]
           • RANGE OF AVAILABLE ADDRESSES
         • DEFAULT ROUTER / GATEWAY
           • R1(DHCP-CONFIG)#DEFAULT-ROUTER ADDRESS [ ADDRESS2 .... ADDRESS8]
         • DNS SERVER
           • R1(DHCP-CONFIG)#DNS-SERVER ADDRESS [ ADDRESS2 ... ADDRESS8]
         • DOMAIN NAME
           • R1(DHCP-CONFIG)# DOMAIN-NAME CISCO.COM
         • DHCP LEASE
           • LEASE ( DAY , MINUTOS , INFINITE )
           • R1(DHCP-CONFIG)#LEASE {DAYS [HOURS [ MINUTES]] INFINITE}
         • NETBIOS SERVER
           • R1(DHCP-CONFIG)#NETBIOS-NAME-SERVER ADDRESS [ ADDRESS2 ... ADDRESS8]
   • DHCPv4 RELAY CISCO IOS
     • IPCONFIG / RENEW
       • THIS COMMAND CAUSES BROADCAST DHCP DISCOVER MESSAGE
       • RENEW THE IPV4 ADDRESSING
     • IPCONFIG /RELEASE
       • RELEASES ALL CURRENT IPV4
     • IP HELPER ADDRESS
       • R1(CONFIG-IF) IP HELPER-ADDRESS ( DHCPV4 SERVER )
         • MUST BE INTERFACE ROUTER GATEWAY LOCAL
         • OTHER SERVICE BROADCAST RELAY
           • NTP ; TACACS ; DNS ; TFTP ;E NETBIOS
         • R1#SHOW IP INTERFACE G0/1
           • VERIFY CONFIGURATION DHCP
       • BETTER SOLUTION WHEN DHCP CLIENT AND DHCP SERVER ARE ON DIFFERENT NETWORKS
     • SERVER DHCP LOCATED IN OTHER NETWORKS
     • SINCE THE ROUTER DOES NOT FORWARD BROADCAST MESSAGES TO OTHER NETWORKS
       • IT MUST BE CONFIGURED TO RELAY DHCPV4 MESSAGES TO THE DHCP SERVER.
     • IPCONFIG /ALL
       • WINDOWS VERIFY ALL CONFIGURATIONS
   • DHCPv4 VERIFICATION COMMANDS
     • R1#SHOW IP DHCP BIDING
       • DISPLAYS A LIST OF ALL IPV4 ADDRESS TO MAC ADDRESS BINDINGS PROVIDED BY THE DHCPV4 SERVICE.
     • R1#SHOW IP DHCP SERVER STATISTICS
       • DISPLAYS COUNT INFORMATION REGARDING THE NUMBER OF DHCPV4 MESSAGES THAT HAVE BEEN SENT AND RECEIVED.
     • R1#SHOW RUNNING-CONFIG | SECTION DHCP
       • DISPLAYS THE DHCPV4 COMMANDS CONFIGURED ON THE ROUTER.