Network Basics (CISCO Network Academy) 10/12

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Learning Network

   Theory and Practice
   Catch up the latest technology

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Cisco Network Academy

   E-Learning Package (3 milion yen for first year, 600,000 yen per year)
   Project Oriented
   Actual management of CISCO Routers
       (too specific for CISCO routers)
   Router's setting is command line driven, not GUI base.

Cisco Network Academy (local access only)

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OSI 7 Layer

APSTNDP

  Please, Do Not Throw Sausage Pizza Away
  Physical, Datalink, Network, Transport, Session, Presentation, Application

   First 3 layers ( Physical, Datalink, Network) are the network.
   Upper 4 leyers are software architectures.
    

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Physical Layer

   Cable
   Connector

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Datalink Layer

   NIC ( Network Interface Circuit)
   Ethernet Packet
   Ethernet Address
   LAN

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Network layer

   Internet
   TCP/IP
   Internet Address
   Routing
   WAN

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Network Domain

   Local Area Network and Wide Area Network

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Broadcast Domain

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Collision Domain

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Repeater

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Switch, Bridge

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Router

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Physical Layer and Cabling

   Category 5 cable

Cabling

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Network Design

Hierachical Network Structure

Hosts and Networks

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Structure of IP address

From binary to decimal

 =IF(MID(C9,1,1)="1",128,0)+IF(MID(C9,2,1)="1",64,0)+IF(MID(C9,3,1)="1",32,0)+IF(MID(C9,4,1)="1",16,0)+IF(MID(C9,5,1)="1",8,0)+IF(MID(C9,6,1)="1",4,0)+IF(MID(C9,7,1)="1",2,0)+IF(MID(C9,8,1)="1",1,0)

From decimal to binary

  =CONCATENATE(IF(E9>127,"1","0"),IF(MOD(E9,128)>63,"1","0"),IF(MOD(E9,64)>31,"1","0"),IF(MOD(E9,32)>15,"1","0"),IF(MOD(E9,16)>7,"1","0"),IF(MOD(E9,8)>3,"1","0"),IF(MOD(E9,4)>1,"1","0"),IF(MOD(E9,2)>0,"1","0"))

conjunction of binary

 =CONCATENATE(IF(MID(C16,1,1)="1",MID(C19,1,1),"0"),IF(MID(C16,2,1)="1",MID(C19,2,1),"0"),IF(MID(C16,3,1)="1",MID(C19,3,1),"0"),IF(MID(C16,4,1)="1",MID(C19,4,1),"0"),IF(MID(C16,5,1)="1",MID(C19,5,1),"0"),IF(MID(C16,6,1)="1",MID(C19,6,1),"0"),IF(MID(C16,7,1)="1",MID(C19,7,1),"0"),IF(MID(C16,8,1)="1",MID(C19,8,1),"0"))

sample ip address computation (Excel Sheet)

32 bit integer

   32                          1
   |---------------------------|

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4 digit representation

   32                        1
   |----| |----| |----| |----|
     8      8      8      8

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Network address

   32                          1
   |---------------|-----------|
     Network No.     Host No.

Number of bit is important

                                           first digit
   class A         8bit Network Number     1-127
   class B         16bit Network Number    128-195
   class C         24bit Network Number    196-223

over 224 is used for multicast etc.

Classless Network

   specified by netmask
   32                          1
   |---------------|-----------|
   |111111111111111|00000000000|
   |---------------|-----------|
     Network No.     Host No.

cf. Structure of IP v6 address

   128 bit  using Netmask
   lower 48 bit can be a physical address (ethernet address)

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Subnet

   32                          1
   |-------|-------|-----------|
   |1111111|1111111|00000000000|
   |-------|-------|-----------|
     Network No.     Host No.
           Subnet 

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Sample Address Computation

binary and decimal

    128    ( 256 / 2)
    64     ( 256 / 4)
    32     ( 256 / 8)
    16     ( 256 / 1)
    8      ( 256 / 3)
    4      ( 256 / 6)

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Example

Class C 220.50.1.0 is divided by 4

    256/4 = 64
    220.50.1.0
    220.50.1.___
    220.50.1.128
    220.50.1.___

Class B 130.50.0.0 is divided by 8

    256*256/8 = ___
    133.50.0.0
    133.50.32.0
    133.50.___.0
    133.50.___.0
    
    133.50.128.0
    133.50.___.0
    133.50.___.0
    133.50.___.0
   

if Class B 130.50.0.0 divided by 16, what kind of range can be used as a subnet.

    133.50.16.__   -  133.50.__.__
    133.50.128.__  -  133.50.__.__