Ip address

Ip address

1. IPv6 network addresses

   • IPv6 addressing
     • IPv6 address representation
       • IPv6 addresses are 128 bits long
         • Every 4 bits are represented with a single hexadecimal digit
     • Rule 1: skip the initial 0
       • It consists of omitting the initial 0 (zeros) in any 16-bit section or hex
         • 01AB can be represented as 1AB.
         • 09F0 can be represented as 9F0.
         • 00AB can be represented as AB.
         • 0A00 can be represented as A00.
     • Rule 2: skip the segments of 0
       • The double colon (: :) can replace any single, contiguous string of one or more 16-bit segments
         • Possible expansions of ambiguous compressed addresses
           • 2001:0DB8::ABCD:0000:0000:1234
           • 2001:0DB8::ABCD:0000:0000:0000:1234
           • 2001:0DB8:0000:ABCD::1234
           • 2001:0DB8:0000:0000:ABCD::1234
   • Types of addresses
     • Unicast
       • Identify an interface of an IPv6 enabled device.
     • Multicast
       • They are used to send a single IPv6 package to several destinations
     • Proximity Diffusion
       • It is any unicast IPv6 address that can be assigned to multiple devices
     • IPv6 prefix length
       • It is used to indicate the network portion of an IPv6 address
   • Unicast
     • They are globally unique and routable on the IPv6 Internet. These addresses are equivalent to public IPv4 addresses.
       • Global Routing Prefix
         • Portion of prefix, or network, of the address assigned by the provider
       • Subnet ID
         • They use the subnet ID to identify subnets within their location
       • Interface ID
         • It is equivalent to the host portion of an IPv4 address.
   • Multicast
     • IPv6 multicast addresses assigned
       • They are similar to IPv4 multicast addresses
         • Multicast addresses can only be destination addresses and not source addresses
           • Multicast Address Assigned
           • Multicast address of requested node
   • Problems with IPv4
     • Need to use IPv6
       • The depletion of the IPv4 address space was the factor that motivated the migration to IPv6.
     • IPv4 has a theoretical maximum of 4300 million addresses.
     • Coexistence of IPv4 and IPv6
       • The IETF created various protocols and tools to help network administrators
         • Dual-stack
         • Tunneling
         • Translation

2. Connectivity verification

   • ICMP
     • ICMPv4 and ICMPv6
       • Allows messages to be sent in case certain errors occur
         • Common ICMP messages to ICMPv4 and ICMPv6 include
           • Host confirmation
           • Destination or service inaccessible
           • Time exceeded
           • Route redirection
   • Test and verification
     • Ping is a test utility that uses ICMP echo request and response messages to test connectivity between hosts.
       • The ping command has a timeout value for the response
       • Connectivity to the local LAN
         • A ping to the gateway indicates that the host interface and router interface that perform the gateway function work on the local network.
           • If the gateway or other host responds, local hosts can communicate correctly on the local network.
       • Connectivity to a remote network
         • The local host can ping an operational IPv4 host on a remote network, as shown in the illustration.
           • If the ping is successful, the operation of the network interconnection can be verified.

3. IPv4 network addresses

   • Binary and Decimal
     • Binary system
       • It consists of the numbers 0 and 1
     • Position notation
       • A digit represents different values according to the "position" that the digit occupies in the sequence of numbers.
     • Decimal Position Notation System
       • Base
         • Identify the numerical base based on 10
       • Number position
         • Position of the decimal number from right to left
           • They represent the exponential value
       • Calculation
         • Increase the base with the exponential value of the position
       • Position value
         • It represents units of thousands, hundreds, tens and units.
   • IPv4 structure
     • Network and host portions
       • When determining the network portion compared to the host portion, the 32-bit sequence must be observed.
         • The network is identified and a portion identifies the host
     • The subnet mask
       • Three dotted decimal IPv4 addresses are configured when an IPv4 configuration is assigned to the host
         • IPv4 address
         • Subnet mask
           • Network / host portion of the IPv4 address.
         • Default gateway
     • Logical AND
       • Comparison of two bits that produce the results
         • The logical AND operation is used for the IPv4 address, bit by bit, with the subnet mask.
     • Prefix length
       • It is the number of bits set to 1 in the subnet mask.
   • IPv4 addresses
     • Assignment of an IPv4 address
       • IP addresses can be assigned to devices statically or dynamically.
     • IPv4 communication
       • Multicast
         • Reduce traffic by allowing a host to send a single packet to a selected group of hosts
       • Diffusion
         • It is used to send packets to all hosts on the network with the broadcast address for the network.
           • It is sent to all hosts of a specific network
       • Unicast
         • It is used for normal host to host communication
           • Host address
   • Types of addresses
     • Public IPv4 Addresses
       • They are addresses that are routed globally between ISP routers
     • IPv4 private addresses
       • They are used by most organizations to assign IPv4 addresses to internal hosts
         • Three forms of communication
           • 10.0.0.0 /8 o 10.0.0.0 a 10.255.255.255
           • 172.16.0.0 /12 o 172.16.0.0 a 172.31.255.255
           • 192.168.0.0 /16 o 192.168.0.0 a 192.168.255.255
     • IPv4 addresses of special users
       • They can be assigned to hosts, but with restrictions on how those hosts can interact within the network.
   • Classless Address Assignment
     • It allowed service providers to assign IPv4 addresses at any address bit limit