Objective 6 --> IP Addressing and Subnetting

IP Addressing

• Required to send data between devices located on different networks

• Each device on a network has a unique IP address, different from all devices on the network

• Both a source and destination IP is required

Internet Corporation for Assigned Names and Numbers (ICANN)

• Responsible for IP address allocation

  • IPv4 depleted in 2011

• DNS Management

• Not for profit

• No ICANN = no global internet

Internet Assigned Numbers Authority (IANA)

• Operated by ICANN

• Coordinates daily key elements for the Internet

• Allocates IPs for 5 regions

IPv4 vs. IPv6

• IPv4 contains 32 bits and uses binary

• IPv6 contains 128 bits and use the hexadecimal system

Why IPv6?

• IPv4 is running out

• IPv6 provides over 340 trillion etc. IP addresses

Network and Host Addressing

• Network portion helps identify routes through a network

• Host portion are for devices connected to a particular network

• Different networks must be separated by routers

Classful Addresses

• Has not been subnetted

• They have predetermined networks and hosts

• Subnet mask is the same as the default mask

IP Class A, B, C —> Characateristics

• Class A, B, C are used for internal hosts

Class A:

• Starts with —> 0-127

• Subnet Mask —> 255.0.0.0/8

Class B:

• 128-191

• 255.255.0.0/16

Class C:

• IP Range 192-223

• 255.255.255.0/24

• There are also Classes D + E

Subnet Mask

• A 32-bit reference number that IDs the network and hosts bits in an IP address

• Based on the binary numbering system

• 1 —> network bit

• 0 —> host bit

Classless Address

• Has been subnetted

• Must have a CIDR notation or subnet mask to know network/host allocation

Classless Inter-Domain Routing (CIDR)

• Method of displaying how many bits are network bits

• 255.255.255.240 = /28

  • Convert each to binary and add them together

Subnetting

• Converting host bits in a classful network to be used as network bits

  • Allows an admin to create more networks

Fixed-Length Subnetting

• Divides an IP network into multiple subnets, all of which are the same size and have an equal number of host addresses

Variable Length Subnetting (VLSM)

• Creates multiple subnets from a single subnet

• More efficient than fixed length subnetting

• It uses multiple subnet masks that are tailored to better match the size of each subnet

• Reduces the number of wasted IP addresses in the subnet