Tag Archives: protocol

NAT Protocol Simplified Explanation

  • The purpose of NAT protocol is to reduce usage of public IPs
  • A host needs a public IP to connect to Internet
  • If the host is part of a LAN with a gateway router, a host can use private IP to make requests to public Internet.
  • The public Internet would see that all the requests are originating from a LAN (i.e. the gateway router)
  • A router has a local LAN IP and a public IP.
  • The request flows as following:
    • A local host in the LAN can make a request to a web server on Internet.
    • The host request goes frpm local host IP and port to the local gateway.
    • The gateway maintains a NAT table.
      • An entry in the NAT table will have the source and destination mapping
        --------------------------------------------------------------------
        Local Host IP | Local Host port | Gateway public IP | Gateway port |
        --------------------------------------------------------------------
        
        • The gateway creates a port that maps request to and from the local host to the public Internet web server.
        • Hence the public server would always see the gateway IP and port and LAN host would be anonymous.
      • NAT is essentially a kind of multiplexing local hosts requests over gateways single IP and multiple ports, assigned to each local host.

Reference

Written with StackEdit.

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NDMP: An open protocol to backup enterprise data

NDMP is an open protocol that enables backup/ restore of data in a heterogeneous environment. A real world case: You have two file servers(filer) from NetApp and EMC. And you want to backup your data without bothering about which filer you’d use.

Here NDMP comes into play. If both the filers are running an NDMP server, you can seamlessly carry out backup and restore. You just concentrate on your backup operation and leave out the details of :
– How data is stored ( you need to know data format though)
– What operating system is running on the filer
– Add/ remove a filer with no problem