1. Network interface(Data link) layer
2. Network layer
3. Transport layer
4. Application layer
Network interface layer
The lowest layer of the TCP/IP model. Its task is to provide access to the transmission physical medium and it differs according to the implementation of the medium.
Network layer
The network layer provides network addressing, routing and datagram transmission. Used protocols that will be of interest further regarding DHCP are IP and ARP.
IP protocol
It is the basic protocol of the network layer and in general the internet as a whole. It sends datagrams, which are independent units that contain information about the destination, source and the sequence number of the datagram. The sequence number is used for message reconstruction, since the delivery order of the datagrams might not be the same as their order in the message and delivery reliability isn't guaranteed at all.
IP protocol versions:
" IP v4 - 32 bit addresses. Provides approximately 4 billion unique addresses which aren't sufficient at present times.
" IP v6 - 128 bit addresses. The transition to v6 will bring (is bringing) higher security, QoS, packet segmentation and many more IP addresses. (the transition from IP v4 to IP v6 must be supported by the system provider)
ARP protocol
The ARP abbreviation stands for Address Resolution Protocol. This protocol is used to find the physical address (MAC) based on a known IP address. If required ARP sends information concerning the wanted address to all the stations in the network - Broadcast. The stations consequently answer with a message containing their MAC. If the wanted device/station is outside the node/segment, the appropriate router will answer instead of it.
Transport layer
The transport layer is implemented only in terminal devices and it adjusts the behavior of the network according to the requirements of the device/application.
Application layer
The application layer is composed of programs that use net services to fulfill the needs of users. Examples of specific protocols are for instance FTP, DNS and DHCP.
Application protocols use TCP, UDP or both services at the same time. So called ports are used to differentiate between application protocols, they represent a type of label of the application. It is possible to change the ports in the settings of the service, but each service has a default port that isn't changed for most services and is used as an unwritten standard.
" FTP = 21
" DNS = 53
" DHCP = 67 + 68
The traditional approach to implementing an intranet is to purchase a software package, modify it for your needs, and install it on your system.
Over the past few years, another option has grown in popularity – the implementation of a web-based solution.
As you consider the choice between installed software and a web-based intranet, here are some considerations:
1. The most important requirement of any intranet is that everyone uses it.
To assure broad-based participation, the intranet must be easy to implement, simple to use, cost-effective to maintain, and offer each individual user the power to post, access and use content in a way that serves their specific needs. In short, the intranet must have value to everyone.
Web-based intranets are designed around this concept. The interface and navigation are consistent with their use of the web – an environment in which they feel in control, using familiar tools.
In contrast, the business world is littered with countless elegant and feature-rich soft-ware based intranets that have failed. Why? Because they represented an alien environment into which the user was expected to venture. Few employees had the time or the interest (or courage) to enter, rendering the intranet impotent, with the powerful tools unused.
This is the plight of traditional, out-of-the-box software solutions. Unlike web-based intranets, they force users into a constrained environment requiring in-depth training, built around rules designed for the group, rather than the individual.
2. Software intranets have unpredictable costs: in time, attention and money.
Software based solutions require extensive internal support. The ongoing expense in both staff time and money takes the focus of your IT group away from mission-critical tasks.
System integration, Implementation, maintenance, technology upgrades, training and user support are all on-going tasks that represent a significant, recurring investment. The cost can be substantial, far exceeding your initial license cost and monthly fee.
3. Web-based intranets offer a predictable cost and cutting-edge technology.
Most web-based solutions offer a fixed monthly fee that covers all maintenance, technology upgrades, training and user support. The costs are predictable, the technology evolutionary, and it's all done with minimal involvement of your IT staff.
It's for these reasons that companies needing broad-based participation in a changing environment are choosing web-based intranets over traditional software solutions.
Over the past few years, another option has grown in popularity – the implementation of a web-based solution.
As you consider the choice between installed software and a web-based intranet, here are some considerations:
1. The most important requirement of any intranet is that everyone uses it.
To assure broad-based participation, the intranet must be easy to implement, simple to use, cost-effective to maintain, and offer each individual user the power to post, access and use content in a way that serves their specific needs. In short, the intranet must have value to everyone.
Web-based intranets are designed around this concept. The interface and navigation are consistent with their use of the web – an environment in which they feel in control, using familiar tools.
In contrast, the business world is littered with countless elegant and feature-rich soft-ware based intranets that have failed. Why? Because they represented an alien environment into which the user was expected to venture. Few employees had the time or the interest (or courage) to enter, rendering the intranet impotent, with the powerful tools unused.
This is the plight of traditional, out-of-the-box software solutions. Unlike web-based intranets, they force users into a constrained environment requiring in-depth training, built around rules designed for the group, rather than the individual.
2. Software intranets have unpredictable costs: in time, attention and money.
Software based solutions require extensive internal support. The ongoing expense in both staff time and money takes the focus of your IT group away from mission-critical tasks.
System integration, Implementation, maintenance, technology upgrades, training and user support are all on-going tasks that represent a significant, recurring investment. The cost can be substantial, far exceeding your initial license cost and monthly fee.
3. Web-based intranets offer a predictable cost and cutting-edge technology.
Most web-based solutions offer a fixed monthly fee that covers all maintenance, technology upgrades, training and user support. The costs are predictable, the technology evolutionary, and it's all done with minimal involvement of your IT staff.
It's for these reasons that companies needing broad-based participation in a changing environment are choosing web-based intranets over traditional software solutions.
You must have seen them. Web addresses like http://tinyurl.com/2gj2z3 which, when you click on them, take you to another web page. Why use them? Are there any risks in using them?
URL stands for Uniform Resource Locator. It's the posh technical term for a web address. Web addresses normally take the form http://www.somesite.com/somepage.html, which is not too much of a problem. But some site names can get very long, and so can page names. The increased use of database-driven sites mean that URLs can get very long indeed, and most of them is computer gobbledygook. They are impossible to type in, if you are reading them in a print article, and often get corrupted by word-wrapping when they appear in an email or blog posting.
An URL shortener is a web service that takes a long address that's hard to type, and turns it into a short one. You should use them in articles for print publication, classified ads, emails, blog and forum postings, anywhere there is a danger that the full address may be corrupted, or that someone may need to type the address into a browser manually.
But there is a danger in using short URLs that may make people afraid to use them. The short address disguises the real destination. This makes it easy for somebody to post an innocent looking message encouraging people to click on a link that takes them to a site which infects their computer with spyware, or something equally undesirable.
Some URL shortening services have tried to address this problem. The most well-known service, TinyURL.com, has an optional preview page that shows you the target address before you go there. But you have to know to type "preview" in front of the address, or visit the site and set it as a permanent option. Those who don't know about this are still vulnerable to deception.
A safe URL shortener would not allow the creation of links to undesirable sites. It would also always display a preview page, so the user always sees where the link is taking them before they go there. xaddr.com uses Internet blacklists to prevent its use to disguise sites that are advertised by spam. Its preview page offers a link to McAfee's Site Advisor, which can be used to check the safety of the destination.
Next time you need to write a long web address, use an URL shortener. But to encourage confidence that no harm will come from clicking the link, pick a safe one.
URL stands for Uniform Resource Locator. It's the posh technical term for a web address. Web addresses normally take the form http://www.somesite.com/somepage.html, which is not too much of a problem. But some site names can get very long, and so can page names. The increased use of database-driven sites mean that URLs can get very long indeed, and most of them is computer gobbledygook. They are impossible to type in, if you are reading them in a print article, and often get corrupted by word-wrapping when they appear in an email or blog posting.
An URL shortener is a web service that takes a long address that's hard to type, and turns it into a short one. You should use them in articles for print publication, classified ads, emails, blog and forum postings, anywhere there is a danger that the full address may be corrupted, or that someone may need to type the address into a browser manually.
But there is a danger in using short URLs that may make people afraid to use them. The short address disguises the real destination. This makes it easy for somebody to post an innocent looking message encouraging people to click on a link that takes them to a site which infects their computer with spyware, or something equally undesirable.
Some URL shortening services have tried to address this problem. The most well-known service, TinyURL.com, has an optional preview page that shows you the target address before you go there. But you have to know to type "preview" in front of the address, or visit the site and set it as a permanent option. Those who don't know about this are still vulnerable to deception.
A safe URL shortener would not allow the creation of links to undesirable sites. It would also always display a preview page, so the user always sees where the link is taking them before they go there. xaddr.com uses Internet blacklists to prevent its use to disguise sites that are advertised by spam. Its preview page offers a link to McAfee's Site Advisor, which can be used to check the safety of the destination.
Next time you need to write a long web address, use an URL shortener. But to encourage confidence that no harm will come from clicking the link, pick a safe one.
To the information security professional wireless networking may be thought of as a four letter word to be avoided at all costs. Regardless of the security implication wireless networking can provide cost efficiency, and because of that wireless technologies are here to stay. While many in the profession believe that wireless networks can be easily compromised, this class will show how the appropriate wireless architecture with the proper security controls can make your wireless network as secure as any other remote access point into your network.
In this three day, wireless security workshop, we will examine the cutting edge of wireless technologies. The purpose of the course is to give you a full understanding of what wireless (802.11) networks are, how they work, how people find them and exploit them, and how they can be secured. This hands-on course is based on real world examples, solutions, and deployments. In this course we will actually set up and use wireless networks, determine the tools to uncover wireless networks, and also look at how to defeat the attempts to secure wireless networks.
Course Completion
Upon the completion of our CISM course, students will have:
Constructed a wireless network architecture
Install and configure 802.1x authentication using Microsoft Windows IAS and Server 2000
Install a wireless access point
Distinguish between 802.11x standards
Defeat Wired Equivalent Privacy
Key Take Aways:
An understanding of wireless networks
A CD of common tools and documentation
An ability to search the internet for updates and more information on wireless networks
Detail of Course Content The following topics will be covered:
Wireless History
Radio Frequency (RF) Fundamentals
WLAN Infrastructure
802.11 Network Architecture
802.1X Authentication
Extensible Authentication Protocol (EAP)/(LEAP)/(PEAP)
Detection Platforms
WLAN Discovery Tools
Kismet
Wireless Sniffers
Conventional Detection
Antennas
Exploiting WLANs
Securing WLANs
Other Wireless Options
Legal Issues including GLBA and ISO-17799
Future
Resources
http://www.acquisitiondata.com/wireless_security.asp
In this three day, wireless security workshop, we will examine the cutting edge of wireless technologies. The purpose of the course is to give you a full understanding of what wireless (802.11) networks are, how they work, how people find them and exploit them, and how they can be secured. This hands-on course is based on real world examples, solutions, and deployments. In this course we will actually set up and use wireless networks, determine the tools to uncover wireless networks, and also look at how to defeat the attempts to secure wireless networks.
Course Completion
Upon the completion of our CISM course, students will have:
Constructed a wireless network architecture
Install and configure 802.1x authentication using Microsoft Windows IAS and Server 2000
Install a wireless access point
Distinguish between 802.11x standards
Defeat Wired Equivalent Privacy
Key Take Aways:
An understanding of wireless networks
A CD of common tools and documentation
An ability to search the internet for updates and more information on wireless networks
Detail of Course Content The following topics will be covered:
Wireless History
Radio Frequency (RF) Fundamentals
WLAN Infrastructure
802.11 Network Architecture
802.1X Authentication
Extensible Authentication Protocol (EAP)/(LEAP)/(PEAP)
Detection Platforms
WLAN Discovery Tools
Kismet
Wireless Sniffers
Conventional Detection
Antennas
Exploiting WLANs
Securing WLANs
Other Wireless Options
Legal Issues including GLBA and ISO-17799
Future
Resources
http://www.acquisitiondata.com/wireless_security.asp
The idea of reading email while lounging by the pool, text or instant messaging while doing the laundry, or lounging in the Jacuzzi listening to your MP3 collection is appealing to us all.
Unfortunately, many, or even most, wireless units don't come with security features already functioning. This may not seem like a big issue to someone who is simply setting up a home network, but there are a number of potential problems you should consider.
The most serious problem is the increase in identity theft. If your network is unsecured, the personal data on your wireless electronic equipment is also unsecured. The order you just placed for a book at Amazon may have given your contact and payment information to an unscrupulous hacker!
Nearly every town in which "WiFi" is common will have "War Drivers" and "War Chalkers" at work. These are people who walk or drive around town with wireless equipment, searching for unsecured networks. The "Chalkers" then live up their name, marking curbs and other public items with chalk so that others can more easily find and exploit your network.
Not all "War Drivers" are hackers, of course. Many just want to use your network for free, but the risk is high if you don't learn how to protect yourself. You can usually find quite a bit of free information as to how to secure your network at the website of your router's manufacturer, or by doing a search in a search engine for a phrase like "secure home wireless."
Beyond the truly malicious, there are also your neighbors who may find your network by accident and enjoy nosing into your activities and using your Internet access at will, slowing down your network speed in the process.
Even many businesses use cheap, home-use quality equipment for their company networks. With the poor security often found on small business networks, anyone with a basic knowledge of wireless can access sensitive company and customer data.
If you are unable to secure your network yourself, there are many service companies who will do it for you. A search of your local yellow pages or an inquiry at your neighborhood computer store should yield professional help and get your private data private again
Unfortunately, many, or even most, wireless units don't come with security features already functioning. This may not seem like a big issue to someone who is simply setting up a home network, but there are a number of potential problems you should consider.
The most serious problem is the increase in identity theft. If your network is unsecured, the personal data on your wireless electronic equipment is also unsecured. The order you just placed for a book at Amazon may have given your contact and payment information to an unscrupulous hacker!
Nearly every town in which "WiFi" is common will have "War Drivers" and "War Chalkers" at work. These are people who walk or drive around town with wireless equipment, searching for unsecured networks. The "Chalkers" then live up their name, marking curbs and other public items with chalk so that others can more easily find and exploit your network.
Not all "War Drivers" are hackers, of course. Many just want to use your network for free, but the risk is high if you don't learn how to protect yourself. You can usually find quite a bit of free information as to how to secure your network at the website of your router's manufacturer, or by doing a search in a search engine for a phrase like "secure home wireless."
Beyond the truly malicious, there are also your neighbors who may find your network by accident and enjoy nosing into your activities and using your Internet access at will, slowing down your network speed in the process.
Even many businesses use cheap, home-use quality equipment for their company networks. With the poor security often found on small business networks, anyone with a basic knowledge of wireless can access sensitive company and customer data.
If you are unable to secure your network yourself, there are many service companies who will do it for you. A search of your local yellow pages or an inquiry at your neighborhood computer store should yield professional help and get your private data private again
Link Load Balancing evens out critical resources on data networks with unpredictable requests issued to a server. For example, a web site with heavy traffic may employ two, three or more servers in a link load balancing program. The link load balancing routines enable a network to “juggle” more traffic that otherwise possible If one server is overwhelmed, the link load balancing scheme forwards them to a different server with extra capacity.
Another aspect to link load balancing concerns the communications channels themselves. In this case the “juggling act” is meant to better distribute processing and communications demands more equitably across the network so that no single a computer is overwhelmed by the demand.
Link Load Balancing - Key Features & Benefits First and foremost is “availability” - 24/7 Application Availability for complete IP Application access. Local and Global Service providers rely on redundancy and link load balancing between servers, WSD units and distributed sites for complete server continuity across global networks
Network Bottlenecks - Link Load Balancing Network managers are constantly seeking new solutions for eliminating bottlenecks and latencies for the fastest performance of all networked applications and web-enabled transactions. The idea link load balancing technology combines both unlimited application scalability with flexible traffic distribution management of data centers and server farms.
Network Security - Link Load Balancing Link load balancing is a key element in the overall network Intrusion Prevention effort. Expert Link Load Balancing guards the network against internal and external attacks such as viruses, worms, Trojans, anti-scanning and protocol anomalies. Above all hovers the ultimate link load balancing challenge and network threat – DOS - Denial of Service.
Remember the song, “Take a load off Annie” Just listening to it makes you feel nice and relaxed… For maximum performance and 100 percent uptime, networks use link load balancing to even out resource use throughout the network.
Another aspect to link load balancing concerns the communications channels themselves. In this case the “juggling act” is meant to better distribute processing and communications demands more equitably across the network so that no single a computer is overwhelmed by the demand.
Link Load Balancing - Key Features & Benefits First and foremost is “availability” - 24/7 Application Availability for complete IP Application access. Local and Global Service providers rely on redundancy and link load balancing between servers, WSD units and distributed sites for complete server continuity across global networks
Network Bottlenecks - Link Load Balancing Network managers are constantly seeking new solutions for eliminating bottlenecks and latencies for the fastest performance of all networked applications and web-enabled transactions. The idea link load balancing technology combines both unlimited application scalability with flexible traffic distribution management of data centers and server farms.
Network Security - Link Load Balancing Link load balancing is a key element in the overall network Intrusion Prevention effort. Expert Link Load Balancing guards the network against internal and external attacks such as viruses, worms, Trojans, anti-scanning and protocol anomalies. Above all hovers the ultimate link load balancing challenge and network threat – DOS - Denial of Service.
Remember the song, “Take a load off Annie” Just listening to it makes you feel nice and relaxed… For maximum performance and 100 percent uptime, networks use link load balancing to even out resource use throughout the network.
Navino launched its search engine gateway service recently. For most of the Internet surfers, search engine gateway is a pretty new concept compared with meta search engine or multi search engine. Put it in simple, it is a web service, which can let you search the best information from the best content providers in one website.
When we try to find information everyday, most of us might go to Google.com. Yes, it's true. Most of the time, Google works well. But does Google return the best information? I guess you would agree that the search engine's ranking algorithm could only give a good answer, but not the best. Well, you may ask, where can I get the BEST? The best weather information? The best book information? The best price for your favorite mp3 player? The short answer is from the brain, from the hand picked information. Therefore, Navino's editors and their users give out that the best weather website is weather.com, the best book website is amazon.com and the best price information is froogle.
Besides best hand picked information resources, Navino also provide the search engine gateway technology. Using this technology, you can search all the best website at Navino. All you need to do is to add a unique search name before your searching keywords.
For example, if you want to search New York's weather, you can search with ‘weather New York' and you will be forwarded to weather.com with the keyword ‘New York'. If you want to search finance books, you can search with ‘book finance' and you will be forwarded to amazon.com with the keyword ‘finance'. If you want to search the best price for your favorite mp3 player, you can search with ‘price mp3 player' and you will be forwarded to froogle with the keyword ‘mp3 player'.
Navino search engine gateway is very convenient for your everyday web surfing. Besides that, Navino also provides its users to customize their own search engine gateway and allows its users to recommend search names for public use.
When we try to find information everyday, most of us might go to Google.com. Yes, it's true. Most of the time, Google works well. But does Google return the best information? I guess you would agree that the search engine's ranking algorithm could only give a good answer, but not the best. Well, you may ask, where can I get the BEST? The best weather information? The best book information? The best price for your favorite mp3 player? The short answer is from the brain, from the hand picked information. Therefore, Navino's editors and their users give out that the best weather website is weather.com, the best book website is amazon.com and the best price information is froogle.
Besides best hand picked information resources, Navino also provide the search engine gateway technology. Using this technology, you can search all the best website at Navino. All you need to do is to add a unique search name before your searching keywords.
For example, if you want to search New York's weather, you can search with ‘weather New York' and you will be forwarded to weather.com with the keyword ‘New York'. If you want to search finance books, you can search with ‘book finance' and you will be forwarded to amazon.com with the keyword ‘finance'. If you want to search the best price for your favorite mp3 player, you can search with ‘price mp3 player' and you will be forwarded to froogle with the keyword ‘mp3 player'.
Navino search engine gateway is very convenient for your everyday web surfing. Besides that, Navino also provides its users to customize their own search engine gateway and allows its users to recommend search names for public use.
With everything becoming available wireless these days a great innovation is the wireless media router. What is a wireless media router? It’s a router that allows the transmission of signals from the router to anywhere in the house that has a receiver.
Wireless routers are becoming more and more popular. They have many uses, one of which is viewing pictures and movies from your computer on your television. This comes in very handy when you have media files that you can’t burn on CD or cannot be played on your DVD player.
A second use would be to transmit paid television. For example if you paid for HBO usually you would be able to only view it on one nominated television. With the wireless media router you can send the signal you television is receiving, HBO, to any other television in the house. You can even change the channel from the remote television while viewing.
The third use would be watching television at a location where an antenna is not available. This means no more long cables leading from room to room just to be able to watch television.
Depending on the amount of receivers you have you can receive the signal from multiple televisions. How does it work? The receivers are connected to the remote televisions. The router takes the signal from the source television and distributes it to the remote televisions by way of the receiver. On the remote television a certain channel is dedicated to this receiver meaning you can watch independent television, and easily switch the channel to the signal being received from the wireless router.
This also makes running your entertainment room a breeze. The receiver can also be hooked up-to a projector making it easy to view anything you wish. This means you will not need to purchase separate DVD players VCR’s for every room.
Wireless routers are becoming more and more popular. They have many uses, one of which is viewing pictures and movies from your computer on your television. This comes in very handy when you have media files that you can’t burn on CD or cannot be played on your DVD player.
A second use would be to transmit paid television. For example if you paid for HBO usually you would be able to only view it on one nominated television. With the wireless media router you can send the signal you television is receiving, HBO, to any other television in the house. You can even change the channel from the remote television while viewing.
The third use would be watching television at a location where an antenna is not available. This means no more long cables leading from room to room just to be able to watch television.
Depending on the amount of receivers you have you can receive the signal from multiple televisions. How does it work? The receivers are connected to the remote televisions. The router takes the signal from the source television and distributes it to the remote televisions by way of the receiver. On the remote television a certain channel is dedicated to this receiver meaning you can watch independent television, and easily switch the channel to the signal being received from the wireless router.
This also makes running your entertainment room a breeze. The receiver can also be hooked up-to a projector making it easy to view anything you wish. This means you will not need to purchase separate DVD players VCR’s for every room.
Home security is an important issue for any person. A person’s home is their castle and they want to feel safe and secure. There are several security measures that can be implemented to ensure security such as alarms but one that ensures peace of mind is a wireless home security camera package.
What’s need in the package is a camera to fit either just outside the front or back door that transmits a wireless signal. The best one to buy would be one that has night vision to ensure you can see everything at night. The second would be a receiver. Some receivers have screens so you can watch what’s going on no matter where you are and others need to be connected to a computer or television to see the transmission.
If connected to a computer or television the live feed from the camera can be directly recorded to a hard drive or a cassette or DVD depending on which is convenient. Several cameras can be implemented to get several signals meaning more coverage of the home and the surrounding area.
These wireless home security packages are common and can be purchased at most electronics stores. They are on the expensive side but are worth the purchase for the kind of technology it has. With almost everything becoming wireless these days it was only a matter of time until cameras became wireless also.
Most people need some sort of security measure in place, not for protection, but for peace of mind that they are safe in their home. Although there are several other measures that can be implemented in terms of security, the wireless home security camera is a valuable tool for keeping an eye on things at all times. It will complement any other security measure you have in place and will not disappoint.
What’s need in the package is a camera to fit either just outside the front or back door that transmits a wireless signal. The best one to buy would be one that has night vision to ensure you can see everything at night. The second would be a receiver. Some receivers have screens so you can watch what’s going on no matter where you are and others need to be connected to a computer or television to see the transmission.
If connected to a computer or television the live feed from the camera can be directly recorded to a hard drive or a cassette or DVD depending on which is convenient. Several cameras can be implemented to get several signals meaning more coverage of the home and the surrounding area.
These wireless home security packages are common and can be purchased at most electronics stores. They are on the expensive side but are worth the purchase for the kind of technology it has. With almost everything becoming wireless these days it was only a matter of time until cameras became wireless also.
Most people need some sort of security measure in place, not for protection, but for peace of mind that they are safe in their home. Although there are several other measures that can be implemented in terms of security, the wireless home security camera is a valuable tool for keeping an eye on things at all times. It will complement any other security measure you have in place and will not disappoint.
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