CCNA - Capitulo 6

CCNA - Capitulo 6

1. NETWORK ACCESS LAYER

   • IEEE 802 - LAN & MAN
     • SUB LAYER
       • LOGICAL LINK CONTROL (LLC) 802.2
         • ALLOW / ENABLE MULTIPLE LAYER 3 SUCH IPV4 AND IPV6 UTILIZE
           • SAME NETWORK INTERFACE AND MEDIA.
         • COMMUNICATE WITH
           • UPPER LAYERS ( INTERNET LAYER 3)
         • SOFTWARE
           • AT THE UPPER LAYERS AND THE DEVICE
         • ADD LAYER 2 CONTROL INFORMATION TO
           • NETWORK PROTOCOL DATA.
         • HARDWARE
           • LOWER LAYERS
         • IT PLACES INFORMATION IN THE FRAME
           • IDENTIFIES NETWORK LAYER
         • CONTROL INFORMATION
           • HELP DELIVER THE PACKET
         • IDENTIFIES WHICH NETWORK LAYER IS BEGING USED FOR THE FRAME
         • TAKES THE NETWORK PROTOCOL DATA IPV4 AND IPV6
           • ADDS LAYER 2 HELPER DELIVER PACKET DESTINATION NODE
       • MEDIUM ACCESS CONTROL (MAC 802.3 ; 802.11 ; 802.15)
         • ENCAPSULATION
           • FRAME DELIMITING
             • SYNCHRONIZATION BETWEEN TRANSMITTING AND RECEIVER
           • ADDRESSING SOURCE AND ADDRESS
             • 6 BYTES - 48 BITS - 12 HEX
               • 1 HEX = 4 BITS
           • ERROR DETECTION
             • TRAILER
               • CRC
           • PACKET (DATA LAYER 3)
         • CONTROLS THE NIC AND OTHER HARDWARE
           • RESPONSABLE FOR SENDING AND RECEIVING DATA ON THE WIRED OR WIRELESS
         • MEDIA ACCESS CONTROL
           • CSMA/CD
             • HALF DUPLEX
             • OBSERVAÇÃO
               • PROVIDES PLACEMENT OF DATA FRAMES ONTO THE MEDIA.
     • ROUTER - ACTING AT LAYER 02
       • 1 ) ACCEPTS A FRAME FROM A MEDIUM
       • 2) DE-ENCAPSULATES THE FRAME
       • 3) RE-ENCAPSULATES THE PACKET A NEW FRAME
       • 4) FORWARDS THE NEW FRAME APPROPRIATE TO THE MEDIUM OF THE PHYSICAL NETWORK
   • SERIAL LINKS DO NOT REQUIRE MEDIA ACCESS CONTROL BECAUSE THEY ARE POINT-TO-POINT CONNECTIONS AND DO NOT NEED TO COMPETE FOR ACCESS WITH ANY OTHER DEVICE.
   • WHAT IT DOES ?
     • ACCEPTS DATA , LAYER 3 PACKET - MTU
       • ENCAPSULATE INTO LAYER FRAME
     • ENABLE UPPER LAYERS
       • ACCESS THE MEDIA
         • THE UPPER LAYER PROTOCOL IS COMPLETELY UNAWARE
           • THE TYPE OF MEDIA USED
     • CONTROL HOW DATA
       • RECEIVED ON THE MEDIA
     • ERROR DETECTION ; REJECT CORRUPT FRAME
     • RESPONSIBLE FOR NETWORK INTERFACE CARD (NIC)
   • DEVELOPMENT PROTOCOLS TCP IP
     • IETF
       • RFCs
   • DEVELOPMENT PROTOCOLS LAYER 2
     • IEEE , ITU , ISO ANSI
   • NODE
     • WHATS IS NODE ?
       • DEVICE CAN RECEIVE , CREATE , STORE OR FORWARD DATA ALONG A COMMUNICATIONS PATH
     • END DEVICE , INTERMEDIARY SUCH ETHERNET SWITCH , ROUTER , FIREWALL
   • FRAME = QUADRO