Networking for cloud

Terms

Network: This is collection or group of hosts/devices communication with each other.
ip address: This is a unique number given to every device on a network.
ip address comes into two formats
- ipv4:
  - This is a 32 bit number
  - This is represented in 4 octets X.X.X.X
  - each octet is 8 bits with minimum value 00000000 (0) to 11111111 to (255)
  - Range of ipv4 is from 0.0.0.0 to 255.255.255.255
- ipv6
  - This is a 128 bit number
Reserved ipv4 ranges

Category	Purpose	Example Range
Private IP	Used for local area network (LAN) communication	10.0.0.0/8
		172.16.0.0/12
		192.168.0.0/16
Loopback	Used for loopback testing on a host	127.0.0.0/8
Link-local	Automatic address assignment for local communication	169.254.0.0/16
Multicast	Used for multicast group communication	224.0.0.0/4
Experimental	Reserved for experimental purposes	240.0.0.0/4

Every ip address is combination of
- network id
- host id
Router: Router is a device which can transfer network packets from one network to other
In public networking a server responds to other server with public ip.

Every network has a range of ip addresses, As long as communication is with in this range, we donot need any external devices.
Generally we communicate to application by giving names (facebook.com), networking protocols only understand ip’s not names
- ip address should be found for the name (DNS resolution)
- if the network id is different then the router will forward the packet to the connected networks
- which will be forwarded to the NAT of service provider which communicates to facebooks and we get the response