TCP / IP

Question 1

IPv4 Addresses

Internet Protocol Version 4

Answer 1

• Internet Protocol Version 4
  
  • OSI Layer 3 addresses

192 . 168 . 1 . 131

11000000 . 10101000 . 00000001 . 10000011

 8bits    =     1byte     =     1 octet |\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_|
              32bits = 4bytes

Question 2

IPv6

Internet Protocol Version 6

Answer 2

• Your DNS will become very important !
• Internet protocol version 6 - 128 bit address
• 340 Undecillion
• 6.8 billion people could have 5 octillion addresses each
• 128 bits = 16bytes
• First 64bits = network prefix / last 64 = Host network

Question 3

IPv6 Address Compression

Answer 3

• Group of zeros can be abbreviated with double colons
  
  • Only one allowed per address

-Leading zeros are optional

-fe80 : 0000 : 0000 : 0000 : cabc : C800 : 00A7 : 08d5
Remove Leading Zeros

            fe80 : 0 : 0 : 0 : cabc : c800 : a7 : 8d5

  Abbreviate 2+ groups of zeros with double colon 

                fe80 : : cabc : c800 : a7 : 8d5

Question 4

APIPA

Automatic Private IP Addressing

Answer 4

-A link-local address

• IETF has reserved 169.254.0.1 through 169.254.0.1
  
  • Firsts & last 256 addresses are reserved
• Automatically assigned
  
  • Uses ARP to confirm the addresses isn’t in current use

Question 5

IPv6 Link-local Addresses

Answer 5

-A non-routable local network address

• Required on every IPv6-enabled interface
  
  • You may see many IPv6 addresses per interface
• fe80 : : / 10 with only one subnet allocated (all zeros)
  
  • Effectively f80 : : / 64

-The last 64bits are usually created with a modified EUI-64

Question 6

Ingredients for Addressing

Answer 6

• IP Address eg 192.168.1.165
  
  • Every device needs unique IP address
• Subnet mask eg 255.255.255.0
  
  • Used by the local workstation to determine what subnet its on
• Default gateway eg 192.168.1.1
  
  • The router that allows you to communicate outside of your network

Question 7

Domain Name System

DNS

Answer 7

-Translate human-related names into computer readable IP address

• Distributed database
  
  • Many DNS servers clusters
  • 13 root server cluster
• IP Address of DNS servers is provided by a network administrator
  
  • Two addresses for redundancy

Question 8

Configuring DHCP

Dynamic Host Configuration Protocol

Answer 8

• IP address configuration used to be static
  
  • IP address , subnet mask, gateway , DNS servers
• Dynamic Host Configuration Protocol
• Turn it off or on

Question 9

CIDR

Classless Inter-Domain Routing

Answer 9

• CIDR (Classless Inter-domain Routing)
• Removed the restrictions created by classful subnet masks
• “CIDR” block notation
• Subnet mask can be expressed as a decimal or in CIDR notation