Networks and VPN

Networks and VPN

Computer Networks and how it relates to Internet Security

Purpose

The purpose of this presentation is to talk about Virtual Private Networks (VPN) from the perspective of security.

Topics Covered: Computer Networks IP Addressing Traffic Routing Security

Networking Terms

Network Switch Connects multiple

computers on network Router

Connects a network to the Internet

Contains a list of its known addresses

Protects its own network from the outside

Ethernet cable Connects a computer

to a network WIFI

A wireless connection to a network

Computer Network

A computer network is a collection of computers that are connected and are communicating.

They generally communicate through a communication device called a network switch, or switch for short.

Network Types

Computer networks come in various types, shapes, and sizes. We’ll talk about the following:

• LAN - Local Area Network• WAN - Wide Area Network• VPN - Virtual Private

network

Local Area Networks

A LAN is a network that is limited to a specific geographical location. Used in a home,

smaller school, or smaller business.

The computers will likely be connected using Ethernet cables or though WIFI.

Wide Area Networks

A WAN is a collection of LANs that are interconnected, or simply, a network of LANs.

A WAN is useful for: Splitting larger

networks Joining together

networks in different geographical locations.

Communication

So, how do these computers communicate?

In order for computers to communicate with each other, they need to have an addressing scheme.

Networks use Internet Protocol addresses(IP addresses).

IP Addresses

An IP address is a numeric number assigned to a device. Each IP address on a particular network is unique.

The IP address tells the networking equipment the device’s location on the network.

Think of it like your house address:

Your street and house number identify your location. However, they may not be unique, but they are unique within your zip code.

Public and Private IP Addresses

An IP address may be public or private.

Public and Private IP Addresses

Think about it like a university mail system.

Public and Private IP Addresses

The student’s mailbox at the university is private and only has meaning to the university.

Public and Private IP Addresses

The university’s address is public and known by the post office.

Public and Private IP Addresses

The post office only knows to deliver the mail to the university.

Public and Private IP Addresses

The university then has the information to know which student’s box the mail goes in.

Routers

Routers direct or route the internet traffic.

When a router receives data with a destination IP address, it knows where to send it.

Routers come in all shapes and sizes and are built for different purposes.

Home router

Commercial router

Routing

The university post office acts like a router: It determines if the

sending student’s mail should go to another student, or if it should go to the public post office to be delivered elsewhere.

When it receives mail from the public post office, it determines what to do with it.

If the student’s mailbox exists, it is delivered. If the student’s mailbox does not exist, the mail is discarded or returned.

Security

Now that you understand how networks operate, let’s talk a bit about security.

Unsecure WAN

Typically, most data across the internet is open and can be intercepted and then downloaded.

For example, if the Field Support Office downloads a document from the Corporate Office, someone could intercept the same document as it is being downloaded.

A VPN can prevent this scenario!

Virtual Private Network

A VPN extends a LAN to a remote user using a public network, such as the internet.

This is possible by creating a secure tunnel from the user to a VPN Server on another network.

Even though the user is physically in a different location, the VPN connection makes it look like the user is physically connected to that LAN.

A WAN using VPN

A VPN creates a tunnel through the Internet.

The data exchange between the office networks are all encrypted.

Each office can now access the data in the other offices as if they were on the same network.

Why use a VPN? Securely access files on a remote LAN with

ease

Cost Effective

Location hiding

VPN – Location Hiding

Tom recently moved to Turkey

Tom needs YouTube for a school assignment

…but, Turkey blocks YouTube

VPN – Location Hiding

Tom has an idea!

Tom connects to his school’s network in the USA via VPN

VPN – Location Hiding

Bingo! He can know access YouTube.

Why? The VPN allowed him to view YouTube as if he was physically connected at his school.

Resources http://www.ehow.com/about_4671848_what-is-vpn.html http://www.ciaograzie.it/listing/poli/tsr/VPN_E_A.pdf http://en.wikipedia.org/wiki/Routing_table http://en.wikipedia.org/wiki/Router http://compnetworking.about.com/od/workingwithipaddresses/a/

subnetmask.htm http://en.wikipedia.org/wiki/IP_address http://en.wikipedia.org/wiki/Computer_network http://en.wikipedia.org/wiki/Virtual_private_network

Image References Gnome Network: http://commons.wikimedia.org/wiki/File:Gnome-

preferences-system-network.svg School IP: http://commons.wikimedia.org/wiki/File:School_ip.svg Router: http://commons.wikimedia.org/wiki/File:Router.svg File Lock: http://commons.wikimedia.org/wiki/File:Lock_icon.png VPN Tunnel: http://commons.wikimedia.org/wiki/File:VPN_remote.jpg RJ45 Jack: http://commons.wikimedia.org/wiki/File:Network-wired.svg LAN Network: http://commons.wikimedia.org/wiki/File:Server-based-

network.svg LAN/WAN Network:

http://commons.wikimedia.org/wiki/File:Gateway_firewall.svg House Number: House Number:

http://commons.wikimedia.org/wiki/File:House_numbering_of_National_Quantum_Information_Centre_of_Gda%C5%84sk.jpg

Image References cont. Mailboxes:

http://commons.wikimedia.org/wiki/File:JMU_student_mailboxes.jpg D-Link Router: http://commons.wikimedia.org/wiki/File:D-Link_DI-524.jpg Cisco Router:

http://commons.wikimedia.org/wiki/File:Cisco_7603_Chassis.png Letter:

http://office.microsoft.com/en-us/images/similar.aspx#ai:MC900127677| Paddle lock: http://commons.wikimedia.org/wiki/File:Abus_Lock.jpg Private sign:

http://commons.wikimedia.org/wiki/File:GWMNM_private_property_sign.jpg Public sign:

http://upload.wikimedia.org/wikipedia/commons/thumb/d/d3/Public_footpath_sign%2C_Alvechurch.JPG/512px-Public_footpath_sign%2C_Alvechurch.JPG

Mail truck: http://commons.wikimedia.org/wiki/File:USPS-Mail-Truck.jpg

Image References cont. Cardiff University:

http://commons.wikimedia.org/wiki/File:Cardiff_University.JPG Tunnel: http://commons.wikimedia.org/wiki/File:Tunnel_42m.jpg Turkey Map:

http://commons.wikimedia.org/wiki/File:Turkey_map_blank.png YouTube: http://commons.wikimedia.org/wiki/File:Youtube.svg No Sign: http://commons.wikimedia.org/wiki/File:No_sign.svg