MultiCloud Classroom notes 27/Nov/2025

Understanding Basic network

• To find ip address on your system

# windows
ipconfig

# linux
ifconfig

• Ip Address: Unique number given to a system within a network.
• Ip Address = network id + host id
• network id is unique identifier for network which remains the same for all devices in a network
• host id is a unique number given to every connected system in a network.
• IP address has 2 variants
  • ipv4: This is a 32 bit number. divided into 4 octets x.x.x.x
  • x => 0 to 255
  • ipv6: This is 128 bit number
• IN my system the ip is

192.168.0.110

• To find network id we need subnet mask
• octets with 255 => network id
• octets with 0 => host id
• Option 1

192.168.0.110
255.255.255.0
--------------
network id => 192.168.0
host id => 110

# Size => 1 octet => 8 bits => 2^8 - 2 => 256 - 2  => 254

• Option 2

192.168.0.110
255.255.0.0
--------------
network id => 192.168
host id => 0.110

# Size => 2 octets => 16 bits => 2^16 - 2 => 65536 - 2 => 65534

• Size of the network =>

n = number of bits in host id

2^n - 2

# all 0's in host id => network id
# all 1's in host id => brodcast ip

• possible subnet mask and sizes

255.0.0.0  => 3 octets => 2^24 -2
255.255.0.0  => 2 octets => 65534
255.255.255.0 => 1 octet > 254

• references
  • 2 power table
  • binary to decimal
  • decimal to binary

Network communication

• A device in a network can communicate with any other device with in the same network.
• Router is a device which can forward packets from one network to another
• Default gateway is ipaddress of your router.