CCNA - Capitulo 15.1

CCNA - Capitulo 15.1

1. LAYER APPLICATION

   • DNS - DOMAIN NAME SERVICE
     • RECORD TYPES
       • A
         • END DEVICE IPV4
       • AAAA
         • END DEVICE IPV6
       • NS
         • AUTHORITATIVE NAME SERVER
       • MX
         • MAIL EXCHANGE RECORD
       • WHEN A CLIENT MAKES A QUERY
         • 1 - SERVER DNS PROCESS FIRST LOOKS AT ITS OWN RECORD TO RESOLVE THE NAME
         • 2 - IF IT IS UNABLE TO RESOLVE THE NAME BY USING ITS STORED RECORDS
           • CONTACTS OTHER SERVERS TO RESOLVE THE NAME
     • DNS MESSAGE SECTION
       • QUESTION
         • THE QUESTIONS OF THE NAME SERVER
       • ASWER
         • RESOURCE RECORDS
           • ASWERING THE QUESTION
       • AUTHORITY
         • RESOURCE RECORDS
           • POITING TOWARD AN AUTHORITY
       • ADDITIONAL
         • RESOURCE RECORDS HOLDING
           • ADDITIONAL INFORMAL
     • SYSTEM HIERARCHICAL
       • NAMIMG STRUCTURE IS BROKEN
         • DOWN INTO SMALL
           • MANAGEABLE ZONES
       • BASED ON ZONES
       • TOP-LEVEL DOMAIN
         • .COM
         • .ORG
           • TYPE OF ORGANIZATION
         • .AU
           • CONTRY OR ORIGIN
         • .CO
       • DATABASE TO PROVIDE NAME RESOLUTION
         • EACH DNS SERVER MANTAINS SPECIFIC DATABASE FILE
           • 1 - ONLY RESPONSIBLE FOR MANAGING NAME TO IP FOR THAT SMALL PORTION DNS STRUCTURE
             • EX : INTRANETS , WEB SERVERS INTERNALS
           • 2 - DNS SERVER RECEIVES REQUEST NAME NOT WITHIN ITS DNS ZONE
             • FORWARDS THE REQUEST TO ANOTHER DNS SERVER
               • EX : WWW.GLOBO.COM
     • NSLOOKUP COMMAND
       • QUERY MANUALLY
     • FQDNs SUCH (HTTP://WWW.CISCO.COM)
       • MUCH EASIER PEOPLE TO REMEMBER THAN 198.133.219.25
     • DNS CLIENT SERVICE WINDOWS - STORE PREVIOSLY RESOLVED NAME IN MEMORY
       • IPCONFIG /DISPLAYDNS
         • CACHE DNS ENTRIES
   • DHCP ( DYNAMIC HOST CONFIGURATION PROTOCOL )
     • ADDRESS POOL
       • DYNAMIC ADDRESSING
     • LEASE TIME
       • HOST TIME STAYS WITH THE IP
       • PERIOD EXPIRES
         • DHCP SERVER RECEIVES
           • DHCP RELEASE MESSAGE
             • THE ADDRESS IS RETURNED TO THE DHCP POOL FOR REUSE
       • DHCPv6
         • OBS ? DHCPv6 DOES NOT PROVIDE A DEFAULT GATEWAY
         • OBTAIN FROM DEFAULT GATEWAY
           • ROUTER ADVERTISEMENT MESSAGE
     • DHCP OPERATION V4
       • 1 - DHCP DISCORVER
         • CLIENT > SERVER
           • IDENTIFY ANY AVAILABLE DHCP SERVERS ON THE NETWORK
         • BROADCAST
       • 2 - DHCP OFFER
         • SERVER REPLIES WITH A DHCP OFFER
           • IPV4 ADDRESS
           • SUBNET MASK
           • LEASE TIME
         • CLIENT MAY RECEIVE MULTIPLE DHCPOFFER IF THERE MORE THAN ONE DHCP SERVER ON THE LOCAL NETWORK
           • CLENT MUST CHOOSE BETWEEN DHCPs
       • 3 - DHCP REQUEST
         • IDENTIFIES THE EXPLICIT SERVER AND LEASE OFFER
       • 4 - DHCP ACK
         • SERVER RETURNS CONFIRMATION MESSAGE
       • DHCP NACK
         • IF THE OFFER IS NO LONGER VALID , THE SELECTED SERVER
           • RESPONDS WITH A DHCP NEGATIVE
         • THEN SELECTION PROCESS MUST BEGIN AGAIN WITH A NEW DHCPDISCOVER
     • ASSIGNMENT OF IPV4
       • GATEWAY
       • DNS
       • IP
     • DHCPv6
       • SOLICIT
       • ADVERTISE
       • INFORMATION REQUEST
       • REPLY
   • SCALABLE