#Network

It's a numerical label (decimal) to locate a device on a network. IP: Internet protocol

Composed of 4 bytes called segments, 246 values available each. A logical pattern to identify subnetworks

IP segment can be btw 0-255 only. A single byte can take 2^8 = 256

IP classes

Public networks - internet Class A - 0.0.0.0 / 127.255.255.255 Class B - 128.0.0.0 Class C Class D Class E

Private networks Class A - 10.0.0.0 / 10.255.255.255 Class B - 172.16.0.0 / 172.31.255.255 Class C - 192.168.0.0 / 192.168.255.255

Addressing

Static or dynamic IP

Static IP : specified on the device by the admin, for devices that don't move much Dynamic IP : provided by DHCP on a network

[[DHCP]] : Dynamic IP address distribution system Network gives us an IP address to avoid conflicts

It's service managing IPs. It can be provided by a router or a server

When device connects to network, it will message the device through 255.255.255.255 DHCP will attribute an address to the device. Device confirms the IP address.

DHCP can be configured to only a pass a range of IP.

Exercise :

A: 192.168.1.7 / 25 B: 192.168.1.121 / 25 C: 192.168.1.130 / 25

how many machines? are they in the same subnetwork? can they intercommunicate?

25 means 7 zeros :: 2^7 :: 128

126 machines in total.

first subnet address: 192.168.1.0 first subnet broadcast: 192.168.1.127

second subnet address: 192.168.1.128 second subnet broadcast: 192.168.1.255