Simple Network Configuration and VLAN

IP Address Class A

Range: 1-126

Default Mask: 255.0.0.0

Hosts: 16 million Hosts

IP Address Class B

Range: 128-191

Default Mask: 255.255.0.0

Hosts: 65,000 Hosts

IP Address Class C

Range: 192-223

Default Mask: 255.255.255.0

Hosts: 254 Hosts

IP Address Class D

Range: 224-239
Reserved for MulticastIP Address Class A

IP Address Class E

Range: 240-254

Reserved for experimental use.

Private IP Class A

Range: 10.0.0.0 - 10.255.255.255

Private IP Class B

Range: 172.16.0.0 - 172.31.255.255

Private IP Class C

Range: 192.168.0.0 - 192.168.255.255

IPv4 Address Structure

32-bit address in four octets (0-255), written in dotted decimal (192.168.1.1)

Classful Addressing (FLSM)

This uses fixed subnet masks, equal-sized subnets, mask not sent in routing updates.

Classless Addressing (VLSM/CIDR)

Variable Length subnets, mask sent in routing updates, efficient use of address space.

Multicast

It is sent to a group of devices; it replaces IPv4 broadcast.

Anycast

Same address assigned to multiple devices; data delivered to the nearest device.

Straight Through Cable

This is used for switch-to-router, switch-to-PC/Server, hub-to-PC/Server.

Crossover Cable

It is used for switch-to-switch, hub-to-hub, router-to-router, PC-to-PC.

WAN

It connects LANs across cities/countries, involves multiple providers, slower links than LAN.