Networking for Cloud Computing

Concepts required

• IPv4 ip addressing
• subnetting
• Routing
• NAT
• Gateways
• DNS
• Virtual Private Networks (VPN)
• WAN (Wide Area Networks)

Networking Basics

• A device/system connects to the network with the help of network interface.
• Network interface gets an ip address which is allocated by DHCP (Dynamic Host Configuration Protocol)
• In our home networks, the DHCP server is inside your router
• DHCP maintains list of available ipaddresses and the whole range of network
• Range of network is ipaddress range
  
• open the command prompt or powershell

ipconfig
ifconfig (mac)

* The details include
* IP Address
* Subnet Mast
* Default Gateway

Ip Address

• Ip Address = Network Id/Address + Device/Host Id/Address

192.168.0.198

• subnet mask helps in seperating network id and hosgt id
• ip v4 is an ip address which is 32 bit and represented in 4 octets
  X.X.X.X
• Each position is 8 bits which is called as octet
• Refer Here for 2 power table
• range of total ip v4 addresses

0.0.0.0 to 255.255.255.255

• Subnet mask is used to findout network id and host id

     1   2  3 4
ip: 192.168.0.10
sm: 255.255.255.0

octects with 255 => 1.2.3

network id: 192.168
host id: 10


ip: 10.10.0.17
sm: 255.255.0.0

network id: 10.10
host id: 0.17

ip: 101.245.1.7
sm: 255.0.0.0

nid: 101
host: 245.1.7

• Two devices can communicate directly if the network id’s match
• For connecting to device which is not part of your network then how ?
  • Router is a device in networking which can forward packet from one network to other network
• When we try to connect to external devices router will have rules defined to forward packets.