URGENT! Networks. (LAN, WAN, Intranet, Extranet, VPN and Internet)?

Question

I can't figure out the difference between LAN and intranet, and also the extranet and VPN.
Btw is the internet a part of them? I am so messed up!
Can someone please explain to me the meaning of each one of these terms and answer my questions? Thanks! :)

Answer 1

Understand the OSI 7 layer model of networking, once you understand that, the rest of the pieces fall together easily.



The Internet is THE public IP network. There is only 1.

The Internet is the interconnection of Intranets.

An Intranet is a private IP network. There can be 1000s

An Extranet is accessing an Intranet over the public IP network (Internet).

VPN the technology used on the Extranet to secure it.



LAN = Local Area Network. Despite the answers above, a LAN is in reference to the physical network. A LAN is limited to a single facility, such as your home or school or building you work in. A LAN can use any layer 2 technology (Ethernet, Token Ring, etc..). A router separates broadcast domains on a LAN.



Broadcast domain = the part of the network where if a device sends out a broadcast frame, it will be seen by all devices on the LAN. Routers separate broadcast domains. An ARP request is example of a broadcast.



WAN = Wide Area Network = a network that usually connects multiple LANs together. Historically a WAN used some other layer 2 protocol than Ethernet, such as Frame Relay. A WAN is L2 / L3 protocol agnostic, the term is intended to mean your are connecting two or more LANs that are separate by a long distance - like NYC to LA.



Intranet is privately owned network that uses the same protocols and tools as the Internet. It's a private organizations IP network. A big company would have it's own Intranet, where the employees access internal websites via tools like Firefox and it uses all the same security mechanisms that the Internet uses. But it's only accessible to the companies employees. An Intranet can be connected to the Internet, but the Intranet part is firewalled off from the Internet.



Extranet and VPN (Virtual Private Network) are sort of one in the same. A VPN implies a secure/encrypted connection from one private network to another private network over a public network. A VPN can be a piece of client software on a PC, connecting securely to a VPN gateway in order for one user to gain access to a company Intranet. A VPN can also be a router running on LAN, that creates a secure connection to a VPN gateway to allow all the users on the LAN side of the router to connect to the company Intranet.



If it helps, in the real world we don't use the terms Extranet or Intranet anymore. We use public and private network.

Answer 2

LAN basically describes physical connectivity on a small scale. Such as a network within a building.



Intranet describes a collection of network devices, computers, and servers within say that same building but can include other LANs. It's basically a privatized Internet



Internet describes a social connection of users and their systems and infrastructures.



VPN is typically an encrypted tunnel established across the Internet to a network in which you would not otherwise have access. This is just one example.

Answer 3

LAN = Local network.

WAN = Wide area network. The Internet is one example of a WAN.

The Intranet is your companies network, consisting of both LAN (in a building) and WAN (between locations). It is also the term used to describe the companies internal web site that is only accessible to people logged into that companies network.

VPN is a secure way of accessing the company intranet across the internet.

Answer 4

LAN = Local Area Network

WAN = Wide Area Network.



LAN is local. example network in your home

but WAN connected the LAN. example is Internet.

Answer 5

LAN is created by a Router.

Intranet is created by a Local ONLY Web Server residing on your LAN.



VPN is for accesses Servers running on your LAN... ie. Database Servers, CRM (Customer Relation Management) Servers, Network Storage, Directory Services... NOT Intranet.



If you Need Intranet Access you would set up an Extranet Access via Port forwarding a port# other than Port 80... as then any Browser can access it...



Extranet is configured with a outside port Other than 80... and protected by Firewall Access.

Answer 6

Lan - any devices that are on one side of a router

WAN - several LANS connected together

Intranet - the entire network that is owned by one entity. normally its a company

Extranet - outside the intranet but used by the company to send data, such as the company's isp

VPN - is a virtual private network. its a protocol that links your computer to a given network somewhere online (you specify the network)

Internet - The global communication network that allows almost all computers worldwide to connect and exchange information.

Answer 7

LAN is Local Area Network. I.e. your network at home. Intranet is a LOCAL network only accessible by those in the organization. Extranet is a website that resides on your intranet, but you have allowed access to specific people outside of the intranet (controlled access to others on the Internet).



VPN is a virtual private network. It is a point to point encrypted connection. One example os its use is when I want to work from home, but need to access the Intranet at the office, I use a VPN connection from my laptop to the router at work. That allows me to see the Intranet, even though I am not inside the actual building it resides in.

Answer 8

The Internet is the whole, big, world-wide thing. The internet even goes into space (the International Space Station has internet)



ALL of the others are smaller part of the internet, each have specific purposes