3.3 Metropolitan Area Network (MAN)

Metropolitan Area Network (MAN)

Metropolitan Area Network (MAN)

A metropolitan area network (MAN) is a network that interconnects users with computer resources in a geographic area or region larger than that covered by even a large local area network (LAN) but smaller than the area covered by a wide area network (WAN). 

The term is applied to the interconnection of networks in a city into a single larger network (which may then also offer efficient connection to a wide area network). It is also used to mean the interconnection of several local area networks by bridging them with backbone lines. The latter usage is also sometimes referred to as a campus network.

Examples of metropolitan area networks of various sizes can be found in the metropolitan areas of London, England; Lodz, Poland; and Geneva, Switzerland. Large universities also sometimes use the term to describe their networks. A recent trend is the installation of wireless MANs.

Advantages 

1. The biggest advantage of MANs is the bandwidth (potential speed) of the connecting links. 
2. This means that resources (such as databases and files) shared on the network can be accessed extremely quickly. 
3. Some installations allow multiple users to share the same high-speed Internet connection, thereby sharing the cost of the service and securing a better quality of service through collective bargaining and economies of scale.

Disadvantages

1. The key disadvantage of MANs is the cost of the cutting-edge technology employed. Also, this equipment generally has to be installed for the first time, as the copper traditionally used for the phone network is generally considered to be too slow to be annexed for this purpose. 
2. The cost is what inhibits the geographical reach of MANs, which is also another drawback.

3.2 Wide Area Networks (WAN)

Wide Area Networks (WAN)

 Wide Area Networks (WAN)

The term Wide Area Network (WAN) usually refers to a network which covers a large geographical area, and use communications circuits to connect the intermediate nodes. A major factor impacting WAN design and performance is a requirement that they lease communications circuits from telephone companies or other communications carriers. Transmission rates are typically 2 Mbps, 34 Mbps, 45 Mbps, 155 Mbps, 625 Mbps (or sometimes considerably more).

Numerous WANs have been constructed, including public packet networks, large corporate networks, military networks, banking networks, stock brokerage networks, and airline reservation networks. Some WANs are very extensive, spanning the globe, but most do not provide true global coverage. Organisations supporting WANs using the Internet Protocol are known as Network Service Providers (NSPs). These form the core of the Internet.

By connecting the NSP WANs together using links at Internet Packet Interchanges (sometimes called "peering points") a global communication infrastructure is formed. NSPs do not generally handle individual customer accounts (except for the major corporate customers), but instead deal with intermediate organisations whom they can charge for high capacity communications. They generally have an agreement to exchange certain volumes of data at a certain "quality of service" with other NSPs. So practically any NSP can reach any other NSP, but may require the use of one or more other NSP networks to reach the required destination. NSPs vary in terms of the transit delay, transmission rate, and connectivity offered.

Typical "mesh" connectivity of a Wide Area Network

A typical network is shown in the figure above. This connects a number of End Systems (ES) (e.g. A, C, H, K) and a number of Intermediate Systems (IS) (e.g. B, D, E, F, G, I, J) to form a network over which data may be communicated between the End Systems (ES).

The characteristics of the transmission facilities lead to an emphasis on efficiency of communications techniques in the design of WANs. Controlling the volume of traffic and avoiding excessive delays is important. Since the topologies of WANs are likely to be more complex than those of LANs, routing algorithms also receive more emphasis. Many WANs also implement sophisticated monitoring procedures to account for which users consume the network resources. This is, in some cases, used to generate billing information to charge individual users.

Advantages

These are similar to those of LAN's except the scale of sharing etc. becomes far greater and can be world-wide.

Disadvantages

Again these are similar to those of LAN's except that issues such as security become even more important as potential hackers could break into a computer system from anywhere in the world rather than having to physically be in a building.

Encryption of secure data such as financial transactions is necessary because it is even easier to intercept data.

3.1 Local Area Network (LAN)

Local Area Network (LAN)

 Local Area Network (LAN)

A local area network (LAN) supplies networking capability to a group of computers in close proximity to each other such as in an office building, a school, or a home. A LAN is useful for sharing resources like files, printers, games or other applications. A LAN in turn often connects to other LANs, and to the Internet or other WAN.

Most local area networks are built with relatively inexpensive hardware such as Ethernet cables, network adapters, and hubs. Wireless LAN and other more advanced LAN hardware options also exist.

Specialized operating system software may be used to configure a local area network. For example, most flavors of Microsoft Windows provide a software package called Internet Connection Sharing (ICS)that supports controlled access to LAN resources.

The term LAN party refers to a multiplayer gaming event where participants bring their own computers and build a temporary LAN.

Bandwidth of LAN is 5 GHz to 50 GHz.

Examples:

The most common type of local area network is an Ethernet LAN. The smallest home LAN can have exactly two computers; a large LAN can accommodate many thousands of computers. Many LANs are divided into logical groups called subnets. An Internet Protocol (IP) "Class A" LAN can in theory accommodate more than 16 million devices organized into subnets.

Advantages

1. A typical LAN network structureHardware such as printers can be shared so individual workstations do not need their own printer. When they print, the data is stored in a queue on a server. The data is then passed to the printer.
2. All the users work can be stored in a central place (the dedicated file server) so a user can access their work through any computer on the network.
3. Software can be shared, software packages are stored on the server and downloaded to workstations as requested. Note that a licence still has to be bought for each copy of the software needed.
4. Data can be shared because database files stored in the server are available to users around the network; data from CD-ROMs can also be shared across the network.
5. Central back-up can take place automatically at regular intervals. A user will usually be able to retrieve work that has been deleted by mistake.
6. Messages can be sent to people working at other computers on the network which can save time and paper.
7. It is possible to set up a local intranet such as that on the KLB school network. The web pages of information can be accessed only over the LAN.  An intranet is free because it does not involve phone links.
8. There is control over users’ access rights to programs and data.

Disadvantages

1. Printing can be slow. Where a lot of workstations are served by only one or two printers, long print queues may develop.
2. A virus can spread more easily. If a virus gets into one computer, it is likely to spread quickly across the network because it will get into the central backing store.
3. As data is shared there is a greater need for security. Users of the network have to have authentication techniques such as user ids and passwords. Unique user ID's control access to the files and settings on the network while passwords prevent unauthorised users from logging onto the network.  Data may also have to be encrypted so that it is meaningless if intercepted.
4. If the server fails, all the workstations are affected. Work stored on shared hard disk drives will not be accessible and it will not be possible to use network printers either.
5. The cost of installing the equipment is greater. Cabling can be expensive to buy and to install.
6. Damage to cables can isolate computers. Some sections of the network can become isolated and will not be able to communicate with the rest of the network.
7. Because networks can be complicated to maintain, a network manager may be need to be employed to run the system.

3. NETWORK

3. NETWORK

 NETWORK

A network consists of two or more computers that are linked in order to share resources (such as printers and CDs), exchange files, or allow electronic communications. The computers on a network may be linked through cables, telephone lines, radio waves, satellites, or infrared light beams.

Advantages

1. Easy Communication and Speed

It is very easy to communicate through a network. People can communicate efficiently using a network with a group of people. They can enjoy the benefit of emails, instant messaging, telephony, video conferencing, chat rooms, etc.

2. Ability to Share Files, Data and Information

This is one of the major advantages of networking computers. People can find and share information and data because of networking. This is beneficial for large organizations to maintain their data in an organized manner and facilitate access for desired people.

3. Sharing Hardware

Another important advantage of networking is the ability to share hardware. For an example, a printer can be shared among the users in a network so that there’s no need to have individual printers for each and every computer in the company. 

This will significantly reduce the cost of purchasing hardware.

4. Sharing Software

Users can share software within the network easily. Networkable versions of software are available at considerable savings compared to individually licensed version of the same software. Therefore large companies can reduce the cost of buying software by networking their computers.

5. Security

Sensitive files and programs on a network can be password protected. Then those files can only be accessed by the authorized users. This is another important advantage of networking when there are concerns about security issues. Also each and every user has their own set of privileges to prevent them accessing restricted files and programs.

6. Speed

Sharing and transferring files within networks is very rapid, depending on the type of network. This will save time while maintaining the integrity of files.

Disadvantages 

1. Breakdowns and Possible Loss of Resources

One major disadvantage of networking is the breakdown of the whole network due to an issue of the server. Such breakdowns are frequent in networks causing losses of thousands of dollars each year. Therefore once established it is vital to maintain it properly to prevent such disastrous breakdowns. The worst scenario is such breakdowns may lead to loss of important data of the server.

2. Expensive to Build

Building a network is a serious business in many occasions, especially for large scale organizations. Cables and other hardware are very pricey to buy and replace.

3. Security Threats

Security threats are always problems with large networks. There are hackers who are trying to steal valuable data of large companies for their own benefit. So it is necessary to take utmost care to facilitate the required security measures.

4. Bandwidth Issues

In a network there are users who consume a lot more bandwidth than others. Because of this some other people may experience difficulties.

Although there are disadvantages to networking, it is a vital need in today’s environment. People need to access the Internet, communicate and share information and they can’t live without that. Therefore engineers need to find alternatives and improved technologies to overcome issues associated with networking. Therefore we can say that computer networking is always beneficial to have even if there are some drawbacks.

There are different types of Network

3.1 LAN - Local Area Network
3.2 WAN - Wide Area Network
3.3 MAN - Metropolitan Area Network

2.6 Hybrid Topology

Hybrid Topology

Hybrid Topology

Hybrid Network topology is and why it finds its application in Wide Area Networks. Hybrid, as the name suggests, is mixture of two different things. 

Similarly in this type of topology we integrate two or more different topologies to form a resultant topology which has good points(as well as weaknesses) of all the constituent basic topologies rather than having characteristics of one specific topology. This combination of topologies is done according to the equirements of the organization.

For example, if there exists a ring topology in one office department while a bus topology in another department, connecting these two will result in Hybrid topology. Remember connecting two similar topologies cannot be termed as Hybrid topology. Star-Ring and Star-Bus networks are most common examples of hybrid network. 

Advantages 

1. Reliable : Unlike other networks, fault detection and troubleshooting is easy in this type of topology. The part in which fault is detected can be isolated from the rest of network and required corrective measures can be taken, WITHOUT affecting the functioning of rest of the network. 
2. Scalable: Its easy to increase the size of network by adding new components, without disturbing existing architecture. 
3. Flexible: Hybrid Network can be designed according to the requirements of the organization and by optimizing the available resources. Special care can be given to nodes where traffic is high as well as where chances of fault are high. 
4. Effective: Hybrid topology is the combination of two or more topologies, so we can design it in such a way that strengths of constituent topologies are maximized while there weaknesses are neutralized. For example we saw Ring Topology has good data reliability (achieved by use of tokens) and Star topology has high tolerance capability (as each node is not directly connected to other but through central device), so these two can be used effectively in hybrid star-ring topology. 

Disadvantages 

1. Complexity of Design: One of the biggest drawback of hybrid topology is its design. Its not easy to design this type of architecture and its a tough job for designers. Configuration and installation process needs to be very efficient.
2. Costly Hub: The hubs used to connect two distinct networks, are very expensive. These hubs are different from usual hubs as they need to be intelligent enough to work with different architectures and should be function even if a part of network is down.
3. Costly Infrastructure: As hybrid architectures are usually larger in scale, they require a lot of cables, cooling systems, sophisticate network devices, etc.

2.5 Tree Topology

Tree Topology

Tree Topology

A tree network is a combination of two or more star networks connected together. Each star network is a local area network (LAN) in which there is a central computer or server to which all the workstation nodes are directly linked. The central computers of the star networks are connected to a main cable called the bus. 

Thus, a tree network is a bus network of star networks.

The illustration shows a tree network with five star networks connected to a common bus. The workstations are shown as small spheres, the central computers of the star networks are shown as larger spheres, connections within star networks are shown as short lines, and the bus is shown as a long, heavy line. The connections can consist of wire cables, optical fiber cables, or wireless links.

The tree network topology is ideal when the workstations are located in groups, with each group occupying a relatively small physical region. An example is a university campus in which each building has its own star network, and all the central computers are linked in a campus-wide system. It is easy to add or remove workstations from each star network. 

Entire star networks can be added to, or removed from, the bus. If the bus has low loss and/or is equipped with repeaters, this topology can be used in a wide area network (WAN) configuration.

In a tree network, a cable failure in one of the star networks will isolate the workstation that it links to the central computer of that star network, but only that workstation will be isolated. All the other workstations will continue to function normally, except that they will not be able to communicate with the isolated workstation. If any workstation goes down, none of the other workstations will be affected.

If a central computer goes down, the entire portion of the network served by it will suffer degraded performance or complete failure, but rest of the network will continue to function normally. If the bus is broken, serious network disruption may occur. If redundancy is needed, the central computers of the star networks can be interconnected in a mesh network topology.

Advantages

1. The tree topology is useful in cases where a star or bus cannot be implemented individually.
2. It is most-suited in networking multiple departments of a university or corporation, where each unit (star segment) functions separately, and is also connected with the main node (root node).
3. The advantages of centralization that are achieved in a star topology are inherited by the individual star segments in a tree network.
4. Each star segment gets a dedicated link from the central bus. Thus, failing of one segment does not affect the rest of the network.
5. Fault identification is easy.
6. The network can be expanded by the addition of secondary nodes. Thus, scalability is achieved.
7. It is an extension of Star and bus Topologies, so in networks where these topologies can't be implemented individually for reasons related to scalability, tree topology is the best alternative.
8. Expansion of Network is possible and easy.
9. Here, we divide the whole network into segments (star networks), which can be easily managed and maintained. 
10. Error detection and correction is easy.
11. Each segment is provided with dedicated point-to-point wiring to the central hub.
12. If one segment is damaged, other segments are not affected.

Disadvantages

1. As multiple segments are connected to a central bus, the network depends heavily on the bus. Its failure affects the entire network.
2. Owing to its size and complexity, maintenance is not easy and costs are high. Also, configuration is difficult in comparison to that in other topologies.
3. Though it is scalable, the number of nodes that can be added depends on the capacity of the central bus and on the cable type.
4. Because of its basic structure, tree topology, relies heavily on the main bus cable, if it breaks whole network is crippled.
5. As more and more nodes and segments are added, the maintenance becomes difficult.
6. Scalability of the network depends on the type of cable used.

2.4 Mesh Topology

Mesh Topology

Mesh Topology

A mesh network is a local area network (LAN) that employs one of two connection arrangements, full mesh topology or partial mesh topology. In the full mesh topology, each node (workstation or other device) is connected directly to each of the others. In the partial mesh topology, some nodes are connected to all the others, but some of the nodes are connected only to those other nodes with which they exchange the most data.

The illustration shows a full mesh network with five nodes. Each node is shown as a sphere, and connections are shown as straight lines. The connections can be wired or wireless.

A mesh network is reliable and offers redundancy. If one node can no longer operate, all the rest can still communicate with each other, directly or through one or more intermediate nodes. Mesh networks work well when the nodes are located at scattered points that do not lie near a common line.

The chief drawback of the mesh topology is expense, because of the large number of cables and connections required. In some scenarios, a ring network or star network may prove more cost effective than a mesh network. If all the nodes lie near a common line, the bus network topology is often the best alternative in terms of cost.

There are two types of  Mesh Topology

1. Full Mesh Topology

In this, like a true mesh, each component is connected to every other component. Even after considering the redundancy factor and cost of this network, its main advantage is that the network traffic can be redirected to other nodes if one of the nodes goes down. Full mesh topology is used only for backbone networks.

2. Partial Mesh Topology

This is far more practical as compared to full mesh topology. Here, some of the systems are connected in similar fashion as in mesh topology while rests of the systems are only connected to 1 or 2 devices. It can be said that in partial mesh,the workstations are ‘indirectly’ connected to other devices. This one is less costly and also reduces redundancy.

Advantages 

1. Data can be transmitted from different devices simultaneously. This topology can withstand high traffic.
2. Even if one of the components fails there is always an alternative present. So data transfer doesn’t get affected.
3. Expansion and modification in topology can be done without disrupting other nodes.

Disadvantages 

1. There are high chances of redundancy in many of the network connections.
2. Overall cost of this network is way too high as compared to other network topologies.
3. Set-up and maintenance of this topology is very difficult. Even administration of the network is tough.

2.3 Ring Topology

Ring Topology

                                   

Ring Topology

A ring network is a local area network (LAN) in which the nodes (workstations or other devices) are connected in a closed loop configuration. Adjacent pairs of nodes are directly connected. Other pairs of nodes are indirectly connected, the data passing through one or more intermediate nodes.

The illustration shows a ring network with five nodes. Each node is shown as a sphere, and connections are shown as straight lines. The connections can consist of wired or wireless links.

The ring topology may prove optimum when system requirements are modest and workstations are at scattered points. 

If the workstations are reasonably close to the vertices of a convex polygon (such as the pentagon shown in the illustration), the cost can be lower than that of any other topology when cable routes are chosen to minimize the total length of cable needed.

A break in the cable of a ring network may result in degraded data speed between pairs of workstations for which the data path is increased as a result of the break. If two breaks occur and they are not both in the same section of cable, some workstations will be cut off from some of the others. When system reliability is a critical concern, a bus network or star network may prove superior to a ring network. If redundancy is required, the mesh network topology may be preferable.

A token ring is a widely-implemented kind of ring network.

Advantages

1. Very orderly network where every device has access to the token and the opportunity to transmit.
2. Performs better than a star topology under heavy network load.
3. Can create much larger network using Token Ring.
4. Does not require network server to manage the connectivity between the computers.
5. Data is quickly transferred without a "bottle neck". (very fast, all data traffic is in the same direction).
6. The transmission of data is relatively simple as packets travel in one direction only.
7. It prevents network collisions because of the media access method or architecture required.
8. Adding additional nodes has very little impact on bandwidth.
9. This type of network topology is very organized. Each node gets to send the data when it receives an   empty token. 
10. This helps to reduces chances of collision. Also in ring topology all the traffic flows in only one  direction at very high speed.
11. Even when the load on the network increases, its performance is better than that of Bus topology.
12. There is no need for network server to control the connectivity between workstations.
13. Additional components do not affect the performance of network.
14. Each computer has equal access to resources.

Disadvantages

1. One malfunctioning workstation or bad port in the MAU can create problems for the entire network.
2. Data packets must pass through every computer between the sender and recipient therefore this makes it slower.
3. Moves, adds and changes of devices can affect the network.
4. Network adapter cards and MAU's are much more expensive than Ethernet cards and hubs.
5. Much slower than an Ethernet network under normal load.
6. A physical ring topology uses a single length of cable interconnecting all computers and forming a loop. If there is a break in the cable, all systems on the network will be unable to access the network. Total dependence upon the one cable.
7. All Network Interface Cards (NICs) on the ring network must operate at the same speed.
8. The MSAU on a logical ring topology represents a single point of failure. If all devices are unable to access the network and there is no cable break, it might be that the MSAU is faulty.
9. Because all stations are wired together, to add a station you must shut down the network temporarily.
10. Difficult to troubleshoot a ring network.
11. In order for all computers to communicate with each other, all computers must be turned on.
12. Each packet of data must pass through all the computers between source and destination. This makes it slower than Star topology.
13. If one workstation or port goes down, the entire network gets affected.
14. Network is highly dependent on the wire which connects different components. 
15. MAU’s and network cards are expensive as compared to Ethernet cards and hubs. 

2.2 Star Topology

Star Topology

Star Topology

A star topology is a topology for a Local Area Network (LAN) in which all nodes are individually connected to a central connection point, like a hub or a switch. A star takes more cable than e.g. a bus, but the benefit is that if a cable fails, only one node will be brought down.

All traffic emanates from the hub of the star. The central site is in control of all the nodes attached to it. The central hub is usually a fast, self contained computer and is responsible for routing all traffic to other nodes.

The main advantages of a star network is that one malfunctioning node does not affect the rest of the network. However this type of network can be prone to bottleneck and failure problems at the central site.

A star network is often combined with a bus topology. The central hub is then connected to the backbone of the bus. This combination is called a tree.

Advantages

1. It is very easy to install and manage star network topology as it is the simplest of the lot when it comes to functionality.
2. It is easy to troubleshoot this network type as all computers are dependent on the central hub which invariably means that any problem which leaves the network inoperable can be traced to the central hub.
3. In star topology, the data packets don't have to make their way through various nodes which makes sure that the data transfer is fast.
4. At the same time, the fact that the data packets only make it through three different points ensures that the data is safe.
5. As the nodes are not connected to each other, any problem in one node doesn't hamper the performance of other nodes in the network.
6. Adding new machines or replacing the old ones is a lot easy in this network topology, as disruption of the entire network is not required to facilitate the same.

Disadvantages

1. The foremost problem with star network topology is the fact that it is highly dependent on the functioning of central hub.
2. The size of the network is dependent on how many connections can be made to the hub.
3. This network type requires more cable as compared to linear bus topology which means the expenses incurred would be relatively high.
4. The performance of the entire network is directly dependent on the performance of the hub. If the server is slow, it will cause the entire network to slow down.
5. If one of the numerous nodes utilizes a significant portion of the central hub's processing capability, it will reflect on the performance of other nodes.

2.1 Bus Topology

Bus Topology

Bus Topology

Bus Topology is the simplest of network topologies. In this type of topology, all the nodes (computers as well as servers) are connected to the single cable (called bus), by the help of interface connectors. This central cable is the backbone of the network and is known as Bus (thus the name). Every workstation communicates with the other device through this Bus.

A signal from the source is broadcasted and it travels to all workstations connected to bus cable. Although the message is broadcasted but only the intended recipient, whose MAC address or IP address matches, accepts it. If the MAC /IP address of machine doesn’t match with the intended address, machine discards the signal.

A terminator is added at ends of the central cable, to prevent bouncing of signals. A barrel connector can be used to extend it.

Bus networks (not to be confused with the system bus of a computer) use a common backbone to connect all devices. A single cable, the backbone functions as a shared communication medium that devices attach or tap into with an interface connector. A device wanting to communicate with another device on the network sends a broadcast message onto the wire that all other devices see, but only the intended recipient actually accepts and processes the message.

Advantages 

1. It is easy to set-up and extend bus network.
2. Cable length required for this topology is the least compared to other networks.
3. Bus topology costs very less.
4. Linear Bus network is mostly used in small networks. Good for LAN.
5. Easy to connect a computer or peripheral to a linear bus.
6. Requires less cable length than a star topology.

Disadvantages

1. There is a limit on central cable length and number of nodes that can be connected.
2. Dependency on central cable in this topology has its disadvantages.If the main cable (i.e. bus ) encounters some problem, whole network breaks down. 
3. Proper termination is required to dump signals. Use of terminators is must.
4. It is difficult to detect and troubleshoot fault at individual station.
5. Maintenance costs can get higher with time.
6. Efficiency of Bus network reduces, as the number of devices connected to it increases.
7. It is not suitable for networks with heavy traffic. 
8. Security is very low because all the computers receive the sent signal from the source.
9. Entire network shuts down if there is a break in the main cable.
10. Terminators are required at both ends of the backbone cable.
11. Difficult to identify the problem if the entire network shuts down.
12. Not meant to be used as a stand-alone solution in a large building.

2. NETWORK TOPOLOGY

2.NETWORK TOPOLOGY

What is a Network Topology?

NETWORK TOPOLOGY

The meaning of physical topology indicates the way in which a network is physically laid out.

It is also known as  physical topology.

In communication networks, a topology is a usually schematic description of the arrangement of a network, including its nodes and connecting lines. There are two ways of defining network geometry: the physical topology and the logical (or signal) topology.

Types of Physical /Network Topology

1.   Bus Topology
2.   Star Topology
3.   Ring Topology
4.   Mesh Topology
5.   Tree Topology
6.   Hybrid Topology

1. DATA COMMUNICATION

DATA COMMUNICATION 

DATA & INFORMATION 

• Data refers to the raw facts that are collected while information refers to processed data that enables us to take decisions.
• Ex. When result of a particular test is declared it contains data of all students, when you find the marks you have scored you have the information that lets you know whether you have passed or failed. 
• The word data refers to any information which is presented in a form that is agreed and accepted upon by is creators and users. 

DATA COMMUNICATION 

• Data Communication is a process of exchanging data or information. 
• In case of computer networks this exchange is done between two devices over a transmission medium. 
• This process involves a communication system which is made up of hardware and software. The hardware part involves the sender and receiver devices and the intermediate devices through which the data passes. The software part involves certain rules which specify what is to be communicated, how it is to be communicated and when. It is also called as a Protocol. 
• The following sections describes the fundamental characteristics that are important for the effective working of data communication process and is followed by the components that make up a data communications system. 

Networking Protocol Questions

Networking Protocol Questions

A worldwide system of connected computer networks.
Internet.

computers that connect to the internet use the _________ protocol suite.

TCP/IP

The internet's IP classification system is defined by the ____________.
Internet Assigned numbers Authority (IANA).

DNS is defined by the ___________.
Internet Engineering Task Force (IETF)

An enormous system of interlinked hypertext documents that can be accessed with a web browser.
World Wide Web (WWW)

Web 2.0 =An interactive type of web experience. It allows users to interact with each other and act as contributors to Web sites as well.


Intranets & Extranets=Used by organizations to share data with select individuals.

Intranet=A private computer network or single Web site that an organization implements in order to share data with employees around the world.

Extranet=Used to share data with sister companies or other partnered organizations.

Virtual Private Network (VPN)=Allows connectivity between two remote networks.

Virtual Private Network (VPN)=A connection between two or more computers or devices that are not on the same private network.

PPTP & L2TP=VPNs normally utilize one of two tunneling protocols.

PPTP=The more commonly used VPN tunneling protocol as well as the less secure option.

PPTP=This VPN tunneling protocol generally includes security mechanisms, and no additional software or protocols need to be loaded.
1723

The Point-to-Point Tunneling Protocol (PPTP) utilizes port __________.
Point to Point Protocol (PPP)

PPTP works within the ___________, which is also used for dial-up connections.
L2TP

A VPN tunneling protocol that utilizes IPsec as its security protocol.
1701

A VPN device or server that allows incoming L2TP connections must have inbound port ________ open.
Firewalls

Used to protect a network from malicious attack and unwanted intrusion.
Firewalls

The most commonly used type of security device in an organization's perimeter.
SPI & NAT

The two two types of firewall technologies built into firewalls.
Packet Filtering

Inspects each packet that passes through the firewall and accepts or rejects it based on a set of rules.
Stateless Packet Filtering

Does not retain memory of packets that have passed through the firewall which makes it vulnerable to IP spoofing attacks.
Stateful Packet Inspection (SPI)

A firewall running this is normally not vulnerable to IP spoofing attacks because it keeps track of the state of network connnections by examining the header in each packet.
Stateful Packet Inspection (SPI)

This function operates at the network layer of the OSI model.
NAT Filtering


Filters traffic according to ports (TCP or UDP)
TCP & UDP

NAT Filtering utilizes ______ or ______.
Application level Gateway (ALG)

Supports address and port translation and checks whether the type of application traffic is allowed.
Application level Gateway (ALG)

This type of Firewall Methodology checks each type of packet coming in and discards those that are Telnet packets.
Circuit level Gateways

These hide information about the private network, but they do not filter individual packets.
Circuit level Gateways

This works at the session layer of the OSI model when a TCP or UDP connection is established.
Proxy Server

Acts as an intermediary between a LAN and the Internet.
Proxy Server

This means "go-between" and acts as a mediator between a private and public network.
Proxy Server

Evaluates requests from clients, and if they meet certain criteria, forwards them to the appropriate server.
Caching Proxy

Attempts to serve client requests without actually contacting the remote server.
HTTP

The most common caching proxy is the _______ proxy, also known as a web proxy, which caches web pages from servers on the Internet for a set amount of time.
HTTP Proxy

This is utilized to save bandwidth on the company's internet connection and to increase the speed at which client requests are carried out.
IP Proxy

Secures a network by keeping machines behind it anonymous; it does this through the use of NAT.
IP Proxy

A basic four-port router will act as an IP Proxy for the clients on the LAN it protects. This is an example of __________.
Internet Content Filter

Filters out various types of Internet activities, such as access to certain Web sites, email, instant messaging, and so on.
Application

An Internet Content Filter, or simply a content filter, is usually applied as software at the ____________ layer of the OSI model.
Network Intrusion Detection System (NIDS)

A type of IDS that attempts to detect malicious network activities by constantly monitoring network traffic.
Network Intrusion Prevention System (NIPS)

Designed to inspect traffic, and, based on its configuration or security policy, it can remove, detain, or redirect malicious traffic in addition to simply detecting it.
Back To Back

This configuration has a DMZ situated between two firewall devices, which could be black box appliances or Microsoft Internet Security and Acceleration (ISA) Servers.
3 Leg Perimeter Configuration

In this configuration, the DMZ is usually attached to a separate connection of the company firewall.
Lan, DMZ, Internet

In the 3-Leg Perimeter Configuration, the firewall has three connections: one to the company _______, one to the _______, and one to the _________.
Extranet

You have been tasked to set up an authentication server on a DMZ that will allow only users from a partner company. What kind of network are you configuring?
PPTP

You are in charge of setting up a VPN that allows connections on inbound port 1723. What tunneling protocol are you going to use?
RRAS

Proseware, Inc., wants you to set up a VPN server. What service in Windows Server 2008 should you use?
DMZ

The IT director has asked you to install a firewall. Which of the following is not a type of firewall?
NMAP

You suspect an issue with one of the ports on the firewall. You decide to scan the ports. Which of the following is the appropriate tool to use?
Proxy

Your client wants a server that can cashe web pages in order to increase the speed of commonly accessed Web sites. What type of server does the client require?
NIDS

The customer you are working for wants a device that can detect network anomalies and report them to an administrator. What type of device is the customer looking for?
DMZ

Your boss asks you to set up an area that is not on the LAN but not quite on the internet. This area will house servers that will serve requests to users who are connecting to your intranet. What type of zone does your boss want you to set up?
L2TP

You have been asked by a client to install a VPN server that can offer unencrypted tunnels by default, or encrypted tunnels by using IPSec. Which of the following services should you choose in order to accomplish this?
PPTN

You have set up a default VPN in Windows Server 2008. However, your boss is not happy with the level of security. She would rather have L2TP combined with IPsec. What tunneling prtocol is running currently on the server?
Web 2.0

Allows users to interact with each other and contribute to Web Sites.
Internet Engineering Task Force (IETF)

The ___________ defines DNS.
World Wide Web (WWW)

The ___________ is an enormous system of interlinked hypertext documents.
Intranet

You have set up a netowrk zone that allows remote access for employees of your company. This is known as a ____________.
L2TP

You install a VPN server that uses inbound port 1701. The server is utilizing the ____________ protocol.
Configure Users

You installed a VPN server and configured a VPN adapter on a client computer. However, the connection cannot be completed from the client to the server. This is because you skipped the ____________ step.
DHCP

The VPN server has been configured and is running properly. however, it has not been configured to hand out IP addresses to clients. When a VPN server is configured this way, the clients obtain their IP addresses from a ___________ server.
Public

A firewall normally has a private and a __________ IP address.
Stateful Packet Filtering

You have installed a firewall that accepts or rejects packets based on a set of rules. This firewall keeps track of the state of the network connection. it is running a type of packet filtering known as __________.
P0

aYou have configured a firewall so that all ports are closed. Now you are attempting to scan the firewall's ports to verify that there are no open ones. you should use the ___________ option within the Nmap port scanning program.
Extranet

What type of network can you set up that is another company's internal network?
VPN

What technology can you use temporarily to connect netowrks from two different companies?
PPTP

Which VPN technology is the most common and the easiest to set up?
1701

What port does L2TP use?
Packet Filtering

Which type of firewall blocks packets based on rules that are based on IP addresses or ports?
Stateful Packet Inspection

What technology used in firewalls keeps tracks of conversations so that it knows what to allow back into a network?
Proxy Server

What acts as a middleman that translates between internal and external addresses and that caches previously accessed web pages so that it can provide those more quickly in the futue?
Network Intrusion Prevention System (NIPS)

What type of device is designed to inspect traffic, detect malicious activities, and take steps to mitigate the malicious activity?
3 leg perimeter configuration

Which DMZ configuration uses one firewall with three interfaces?
IPSec

What protocol is used with L2TP to provide encryption?
Circuit level Gateway

What type of firewall works on the Session layer that creates a connection and allows packets to flow between the two hosts without further checking?
Internet Content Filter

What type of firewall do you use to block access to certain websites or instant messengers?
Layers

When trying to protect your network, you should create your secure network based on ____________.
Firewall

What device is used to protect one network from another by using filtering packets?