Saturday, July 24, 2010
What are Information Systems?The largest growth in most economies is coming from 'information' industries. The success of such knowledge-based organis
Thursday, July 22, 2010
The following topics are covered in this module:
Functions, Subroutines, and Properties
After completing this module, you will be able to:
Describe the changes to data types in Visual Basic .NET.
Declare and initialize variables and arrays.
Use shorthand syntax to assign values to variables.
Implement functions and subroutines.
Call the default properties of an object.
Use the new Try…Catch…Finally statement to implement structured exception handling.
The following topics are covered in this module:
Describing the Integrated Development Environment
Creating Visual Basic .NET Projects
Using Development Environment Features
Compiling in Visual Basic .NET
After completing this module, you will be able to:
Describe the overall benefits of the new IDE.
Describe the different types of Visual Basic .NET projects and their structures, including their file structures.
Reference external applications from your project.
View and set the properties of a project.
Use the various windows in the IDE, including Server Explorer, the Object Browser, and the Task List.
Debug a simple application.
Build and compile a simple application.
The following topics are covered in this module:
What Is the Microsoft .NET Platform?
What Is the .NET Framework?
What Are the .NET Framework Components?
What Are the Visual Basic .NET Enhancements?
After completing this module, you will be able to:
List the main elements of the .NET Platform.
Describe the .NET Framework and its components
List the major enhancements to Visual Basic .NET
IDS has the infrastructure facilities to provide in-house training. It also provides on-site training to its clients.
The training imparted may be project specific or it could be a general one taken with a view to obtain certification.
The training provided by IDS include the following technologies:
- Visual Basic.Net
The links to the sites of affiliate sites of IDS are as given below.
IDS possess the project management expertise to implement small and medium size software projects across all its phases - scope definition, design, documentation, testing, training, implementation and post-implementation support.
IDS can provide finite timeline project services to define and reliably manage the project execution. It can provide a mix of on-shore and offshore services to further prune the costs by outsourcing the components of software for which proven expertise is available.
The projects IDS can execute include but are not limited to -
Founded in 1995 IDS has lived through the boom and bust phase of the late nineties in the software era. Now as the software technologies mature and the hype gives way to new realities, IDS has withstood the test of time and under the able leadership of its founders moving ahead to higher trajectories of growth.
Senior and qualified professionals comprise IDS. The all post-graduate management team has over 100 man-years of computer related expertise. IDS is the right company to seek new perspectives and systems to improve productivity and reduce costs.
Information Data Systems (IDS) is an Information Technology and Multi-Project Management firm dedicated to provide custom made solution to customer's need of any size within global reach. IDS provides end-to-end solution with faster implementation at an economical cost.
IDS's core business is focused on providing application development and management solutions to our clients. IDS's vast experience with outsourcing projects has enabled us to cultivate strategic relationships around the globe with clients in multiple industries. These capabilities, experiences and relationships give IDS, the expertise as well as the knowledge capital to help us achieve a competitive advantage in the marketplace.
Wednesday, July 21, 2010
CIDR aggregation requires the network segments involved to be contiguous (numerically adjacent) in the address space. CIDR cannot, for example, aggregate 192.168.12.0 and 192.168.15.0 into a single route unless the intermediate .13 and .14 address ranges are included (i.e., the 192.168.12/22 network).
Internet WAN or backbone routers (those that manage traffic between Internet Service Providers) all generally support CIDR to achieve the goal of conserving IP address space. Mainstream consumer routers often do not support CIDR, therefore private networks (including home networks) and even small public networks (LANs) often do not employ it.
- 192.168.12.0/23 = 192.168.12.0/24 + 192.168.13.0/24
Additionally, CIDR supports Internet address allocation and message routing independent of the traditional class of a given IP address range. For example,
CIDR is an alternative to traditional IP subnetting that organizes IP addresses into subnetworks independent of the value of the addresses themselves. CIDR is also known as supernetting as it effectively allows multiple subnets to be grouped together for network routing.
Backbones typically consist of network routers and switches connected by fiber optic or Ethernet cables. Computers normally do not connect to a backbone directly. Instead, the networks of Internet service providers or large organizations connect to these backbones and computers access the backbone indirectly.
On Windows and Unix/Linux computers, the netstat -r command also displays the contents of the routing table configured on the local computer.
Home routers set up their routing tables automatically when connected to the ISP, a process called dynamic routing. They generate one routing table entry for each of the ISPs DNS servers (primary, secondary and tertiary if available) and one entry for routing among all the home computers. They may also generate a few additional routes for other special cases including multicast and broadcast routes.
Most residential network routers prevent you from manually overriding or changing the routing table. However, business routers typically allow network administrators to manually update or manipulate routing tables. This so-called static routing can be useful when optimizing for network performance and reliability.
Routing tables contain a list of IP addresses. Each IP address identifies a remote router (or other network gateway) that the local router is configured to recognize. For each IP address, the routing table additionally stores a network mask and other data that specifies the destination IP address ranges that remote device will accept.
Home network routers utilize a very small routing table because they simply forward all outbound traffic to the Internet Service Provider (ISP) gateway which takes care of all other routing steps. Home router tables typically contain ten or fewer entries. By comparison, the largest routers at the core of the Internet backbone must maintain the full Internet routing table that exceeds 100,000 entries and growing as the Internet expands.
Two hypothetical, partial routing table entries are shown below:
- IP Address: 18.104.22.168 - Network Mask: 255.255.255.255
IP Address: 192.168.1.1 - Network Mask: 255.255.255.0
The primary Spanning Tree Protocol (STP) is IEEE standard 802.1D, an algorithm commonly used on Ethernet networks. This algorithm works by limiting the paths messages can travel at any given time to a fully connected tree rather than a mesh. As hosts join and leave the network, this protocol dynamically updates the tree accordingly.
A variant of STP called Rapid Spanning Tree Protocol (RSTP) is also now part of the IEEE standard and is the recommended version for use today. RSTP improves the performance of spanning tree updates when the network configuration changes.
Most computer networks direct messages from source to destination devices using any of three techniques called routing, switching and bridging. Routers use certain network address information contained inside messages to send them ahead to their destination (often via other routers). Switches use much of the same technology as routers but typically support local area networks only. Bridging allows messages to flow between two different types of physical networks.
The technologies used to connect to the Internet are different than those used for connecting devices on local area network. DSL, cable modem and fiber provide fixed broadband Internet service, while WiMax and LTE additionally support mobile connectivity. In geographic areas where these high-speed options are unavailable, subscribers are forced to use older cellular services, satellite or even dial-up Internet instead.
The OSI model also makes network designs more extensible as new protocols and other network services are generally easier to add to a layered architecture than to a monolithic one.
The OSI model is a technology standard maintained by the International Standards Organization (ISO). Although today's technologies do not fully conform to the standard, it remains a useful introduction to the study of network architecture.
In computer networking, some network protocols send and receive data in the form of bit sequences. These are called bit-oriented protocols. Examples of bit-oriented protocols include PPP.
Finally, special digital numbers called "keys" are often used to encrypt data on computer networks. The length of these keys is expressed in terms of number of bits. The greater the number of bits, the relatively more effective that key is in protecting data. In wireless network security, for example, 40-bit WEP keys proved to be relatively insecure but the 128-bit or larger WEP keys used today are much more effective.
A wireless network offers advantages and disadvantages compared to a wired network. Advantages of wireless include mobility and elimination of unsightly cables. Disadvantages of wireless include the potential for radio interference due to weather, other wireless devices, or obstructions like walls.
Wireless is rapidly gaining in popularity for both home and business networking. Wireless technology continues to improve, and the cost of wireless products continues to decrease. Popular wireless local area networking (WLAN) products conform to the 802.11 "Wi-Fi" standards. The gear a person needs to build wireless networks includes network adapters (NICs), access points (APs), and routers.
Computer networks also differ in their design. The two types of high-level network design are called client-server and peer-to-peer. Client-server networks feature centralized server computers that store email, Web pages, files and or applications. On a peer-to-peer network, conversely, all computers tend to support the same functions. Client-server networks are much more common in business and peer-to-peer networks much more common in homes.
A network topology represents its layout or structure from the point of view of data flow. In so-called bus networks, for example, all of the computers share and communicate across one common conduit, whereas in a star network, all data flows through one centralized device. Common types of network topologies include bus, star, ring and mesh.
Tuesday, July 20, 2010
Cisco's UCS still has improvements to make before making good on its "cloud in a box" marketing slogan, says StorageIO's Schulz. One of the largest gaps to be filled is the storage solution.
To that end, Cisco is likely to look to longtime partner -- and VMware parent company -- EMC Corp. to shore up its storage story. The two companies have already announced an expansion of their strategic alliance. With the launch of UCS, they'll focus on testing products for interoperability and on developing data center solutions and support offerings.
While acknowledging that EMC is the likely storage partner, StorageIO's Schulz believes the field is open. "The question is, whose storage can work well? Who else can and will be part of the Cisco ecosystem?" he asks.
"When those questions are answered, UCS has the potential to change the playing field," Schulz says. "Virtualization has done more than outgrown traditional IT architecture and deployment processes. It's also upset conventional thinking in the data center."
Current environments are often comfortable with the silos of server, storage and network control, and vendors have relied on those silos to nurture and protect relationships. But that thinking is becoming increasingly obsolete. In order to gain market share, UCS will need to gain an even greater share of mind. Cisco is repositioning itself as a virtual infrastructure management vendor, and, as such, will have to convince the industry that it's time for a pre-packaged cloud in a box. If it can't, the cloud could dissolve in a puff of wind.
Of course, those major server OEMs may not see it the same way. Their countermeasures may include, for example, a little tit for tat: they may consider replacing networking components heretofore provided by Cisco with hardware from Juniper Networks Inc. or Brocade.
Another hurdle Cisco faces in adoption of UCS is that it has no history of building servers. "No one is clamoring for another server vendor, so despite the strong showing of partners at this launch, Cisco will have to win over enterprise server buyers who, up to this point, have had no relationship with the company," wrote Staten and Schreck in their blog.
The only conceptually direct competition to UCS comes from Marlboro, Mass.-based Egenera Inc. Egenera's Processor Area Network (PAN) Manager essentially abstracts server and network resources in the same way a Storage Area Network abstracts storage resources.
Like Cisco's new system, PAN Manager pools physical and virtual resources into a blade platform. The company now works with OEMs to integrate PAN Manager onto additional hardware platforms. The company boasts a strong OEM relationship with Dell, which places PAN Manager on the PowerEdge M610 blade servers.
Egenera chief marketing officer Christine Crandell says the unified architecture is the solution to the "complexity conundrum" that surrounds the presence of many silos in a data center and the difficulty involved in managing them. "The savings for the high-end data center in CAPEX/OPEX is up to 70 percent," she says.
The drivers that Egenera identifies for its installed base of about 1,300 customers include single-vendor support, the simplicity of a "wire once" approach and the fluidity provided by software-based virtualization.
HP's most similar offering is HP Matrix, a converged software, server, storage and networking platform that automates service delivery for the data center. HP Matrix Orchestration Environment provides a unified management interface to design, deploy and optimize the application infrastructure. Together, these offerings create an integrated pool of resources that operate in both physical and virtual environments, creating a pre-packaged infrastructure.
HP is highlighting the virtualization aspects of HP Matrix, with the bundling of HP Insight Capacity Advisor Virtualization Service into the infrastructure. The service, according to HP, helps customers assess, plan and design their virtual environment. HP Insight Capacity Advisor consolidation software identifies the best approach for reducing the risk of downtime, increasing responsiveness and helping maximize the return on investment of a virtualized deployment, according to the company.
Which environments would find UCS most appealing, and which would be interested in switching from existing solutions to the new architecture? Mark Bowker, an analyst with Milford, Mass.-based Enterprise Strategy Group, suggests the "architecture would be especially appealing to high-end data centers [that] see benefits in cloud computing and have the requirement for it."
Cloud computing is making the rounds in IT today as one of the hottest computing paradigms in which tasks are assigned to a combination of connections, services and software that are accessed over a network. This network of servers and connections is collectively known as "the cloud." Leveraging the scale of the cloud allows users to access exceptional processing power through large-scale cluster computing and server virtualization.
Indeed, the required investment, including power draw and footprint as well as acquisition costs, might be prohibitive for midrange organizations. Wolf, on the other hand, believes UCS could be a fit for midsize companies. "I wouldn't rule out the midrange, where the midrange is 50 to 500 servers," he says.
Wolf believes Cisco will fight an uphill battle in the competitive blade server market. "With solutions like OpenView [from] HP, you need a compelling reason to change," he says. In part, that's because high-end data centers may be hesitant to manage a greater mix of server platforms than they already do. Additionally, major new products frequently have a long proof-of-concept period, and the recession has placed even greater limits on IT budgets and personnel.
Because Cisco is new to the server world, potential customers would have to be convinced that Cisco's commitment to its new architecture is a lasting one, says Greg Schulz, principal analyst and infrastructure consultant at The StorageIO Group. "Even enterprise data centers willing to switch will be making a major time and resource commitment just to evaluate, let alone deploy [it]. UCS must be available for the long haul," he explains.
Schulz suggests that Cisco has developed UCS not as a head-to-head competitor for former partners Hewlett-Packard Co., IBM Corp. and Dell Inc., but as an integrated platform that offers all data center building blocks in a unified form factor.
Windows Server 2008 includes Hyper-V R2, Microsoft's base hypervisor. Hyper-V R2 includes important scalability upgrades like Live Migration, which moves running VMs off of one physical server to another with no downtime; quadrupled processor support, all the way up to 64 logical processors; and support for up to 384 concurrently running VMs.
Combined with the management capabilities of System Center -- including Virtual Machine Manager specifically for virtual environments, and a SQL back-end -- Microsoft hopes these components add up to a compelling reason to choose its stack over the competition.
Whatever virtualization solution is chosen, it'll be sitting on an impressive hunk of metal, at least according to initial specs. A family of fabric interconnects, the UCS 6100 series provides line-rate, low-latency 10 Gbps Ethernet and Fibre Channel (FC) over Ethernet switches that consolidate I/O within the system. Twenty-port and 40-port versions include expansion modules that provide FC or 10GigE connectivity. The blade server chassis, called the UCS 5100, accepts up to eight blade servers and up to two fabric extenders in a 6RU enclosure. The fabric extenders, called the UCS 2100 series, bring unified fabric into the chassis, providing up to four 10Gbps connections each between blade servers and the fabric interconnects.
The B-Series blade servers, built on Xeon processors, use network adapters for access to the unified fabric. Cisco points to the servers' memory-expansion technology to increase the memory footprint for the kind of performance that virtualization and heavy workloads require. The network adapters are provided as mezzanine cards -- three separate adapters that are optimized for virtualization, compatibility with existing driver stacks and high-performance Ethernet.
Alternatively, a virtualization-optimized network adapter option uses Single Root I/O Virtualization (SR-IOV), a standard for allowing a physical network adapter to present multiple virtual adapters to upper-level software, typically the hypervisor.
The UCS architecture is built on the promise of power and scalability. It's made to handle workloads much greater than the five to 10 virtual machines (VMs) per physical server normally seen on today's machines.
But Burton Group analyst Chris Wolf generally cautions his clients against an excess of VM density. "Too much virtual machine density puts virtual machine availability at risk when a server failure takes place," Wolf says.
While that may be true, greater efficiency and cost savings occur with greater VM density, which is a key draw of UCS. It's also why the major virtualization platform vendors like VMware, Citrix and Microsoft are partnering with Cisco to get their stacks on the hardware.
VMware got the most face time among those companies at the unveiling of UCS, but Microsoft has a lot to offer. In fact, it's pushing a soup-to-nuts suite of offerings that includes Windows Server 2008, System Center and SQL Server.
August 2009 — It was code-named "California" and is expected to link computing, network, storage, access and virtualization capabilities together into one cohesive system. Now known as the Unified Computing System (UCS), the new platform from Cisco Systems Inc. has moved the company beyond pure-play networking into the server space with virtualization as the defining feature. And Cisco has lined up two big virtual fish for support -- Microsoft and VMware Inc.
"The Cisco Unified Computing System offers a clean-sheet approach to solve data center challenges by offering a single, holistic solution with integrated management and the critical support necessary for scaling virtualization," says Vernon Turner, senior vice president of Enterprise Infrastructure, Consumer and Telecom Research at IDC. "By increasing the performance and scale of virtualized environments, while at the same time improving the ability to control and manage virtual workloads, this solution has the potential to deliver the full benefits of virtualization across the data center to increase productivity and agility and reduce IT costs."
by Bridget McCrea
December 2009 — One of the biggest expenses with a new wireless network can be the controllers. After all, for every 50, 100 or 200 access points (APs) -- the number of APs a controller can handle varies widely, depending on the network type and the vendor, among other things -- you need another wireless controller. That single item might run $25,000 or more, punching a significant hole in a wireless budget.
Sweet Briar College, a small, 108-year-old women's college in Virginia with a nine-to-one student-faculty ratio, got around the controller issue completely by going with a wireless 802.11n network scheme in which the controllers are located off campus, or "in the cloud." That decision saved Sweet Briar enough money that it was able to buy half as many APs as it had originally planned, and to jump from an 802.11g network to state-of-the-art 802.11n.
"The old system was functional on a basic level," said Boise State network engineer Diane Dragone. "But there were a lot of things lacking." Changing a name in the DNS with the Cisco suite required scrolling through a list to find the proper entry, and the vendor tags needed for the DHCP had to be customized for Registrar. "We were looking for more functionality in management," Dragone said. The university, Idaho's largest, settled on the Adonis DNS-DHCP management appliance from BlueCat Networks. The 1000 model server was installed in a test mode in June, moved to production in July and fully implemented by early August. "Once I tested the features and reliability and we were satisfied, I just made an aggressive schedule" for rolling the new management service out across 175 buildings on the 170-acre campus, Dragone said. "The first three weeks or so that I played with it there was a learning curve," but there have been no problems since. DNS and DHCP are critical services that underlie IP networks. DNS associates domain names used by people with the numeric IP addresses used by computers and networking equipment to route and deliver traffic. DHCP lets systems dynamically assign IP addresses from a range of available addresses as devices come onto and leave a network. DNS had been a static service that required little active management, making it what Branko Miskov, BlueCat director of product management, called the forgotten service. DHCP often requires even less attention. "For the most part, DHCP works in the background," Miskov said. "The value added by management has been in monitoring and reporting activity, providing visibility." For those reasons, until recently, management tools for DNS and DHCP have focused on larger enterprises that require staff members to keep up with network name and address changes. "In a large network, you could be making dozens of DNS changes a day," he said. But as network complexity has increased, the market for management tools has moved downstream. "It's not just large organizations that have large networks," he said. The proliferation of mobile networked devices and services, such as VoIP, have made active management of those resources more important.
Changing a name in the DNS with the Cisco suite required scrolling through a list to find the proper entry, and the vendor tags needed for the DHCP had to be customized for Registrar. "We were looking for more functionality in management," Dragone said.
The university, Idaho's largest, settled on the Adonis DNS-DHCP management appliance from BlueCat Networks. The 1000 model server was installed in a test mode in June, moved to production in July and fully implemented by early August.
"Once I tested the features and reliability and we were satisfied, I just made an aggressive schedule" for rolling the new management service out across 175 buildings on the 170-acre campus, Dragone said. "The first three weeks or so that I played with it there was a learning curve," but there have been no problems since.
DNS and DHCP are critical services that underlie IP networks. DNS associates domain names used by people with the numeric IP addresses used by computers and networking equipment to route and deliver traffic. DHCP lets systems dynamically assign IP addresses from a range of available addresses as devices come onto and leave a network.
DNS had been a static service that required little active management, making it what Branko Miskov, BlueCat director of product management, called the forgotten service. DHCP often requires even less attention.
"For the most part, DHCP works in the background," Miskov said. "The value added by management has been in monitoring and reporting activity, providing visibility."
For those reasons, until recently, management tools for DNS and DHCP have focused on larger enterprises that require staff members to keep up with network name and address changes. "In a large network, you could be making dozens of DNS changes a day," he said.
But as network complexity has increased, the market for management tools has moved downstream. "It's not just large organizations that have large networks," he said. The proliferation of mobile networked devices and services, such as VoIP, have made active management of those resources more important.
Back when I had a corporate job, I had a boss with an unorthodox philosophy regarding training. Rather than sending the entire staff out for training, he usually only sent me. Upon completion of the course, it was my responsibility to train my staff on the material I'd just learned.
At first I wasn't pleased with this arrangement. However, I soon realized there were benefits beyond the money the company saved by not sending everyone to training classes.
The place where I took the training classes had a policy that allowed you to retake any class for free once you had paid for the initial session. Because I was responsible for training my subordinates, I made an arrangement with my boss that allowed me to take each class twice; often back to back. This helped me in a few different ways.
First, it meant that I got to spend a lot less time in the office dealing with day-to-day support issues. That was definitely a good thing. More importantly, though, taking classes back to back helped me absorb much more of the material than I would have been able to if I'd only taken each class once. That better prepared me for teaching the material to others in my department and for passing the certification exams.
Finally, spending so much time in training helped me to build a good relationship with the trainers at the facility. This was probably the greatest benefit of all, because any time that I ran into a jam on the job, I was able to pick up the phone and ask one of my buddies at the training facility for advice. Needless to say, doing so was much less expensive than opening a Microsoft support incident.
As you can see, I've picked up a lot of different techniques over the years for getting free or cheap IT training. These techniques all work well, but don't forget another great resource: the Internet. The Internet is chock-full of free technical articles and webcasts on just about any subject imaginable.
There's a series of commercials on late-night television that advertise video-based training for computer novices. Although I can't help but laugh every time I see these corny commercials, video-based training is actually a good idea. After all, for far less money than it costs to attend a Microsoft certification class, you can have a video-based class that you can play over again any time you want. More importantly, though, video-based training makes it possible to train the rest of your IT staff at no additional cost. You pay for the video once, and then use it in whatever way is the most beneficial to your organization.
There are several good video-based training products on the market. One that I particularly like is Clip Training. The essence of Clip Training is that, rather than requiring you to watch a huge, monolithic video, the program is task-oriented. In other words, you can simply click on the task you need to know -- for example, setting up an Exchange mailbox -- and then watch a short video that shows you how to perform the task.
Another video-based training product that I find useful is the Video Mentor series from Pearson Education. These videos go into a lot more depth than the Clip Training and are very similar to attending a certification class.
Prior to going freelance, I worked for several different companies as a network administrator. One of those companies had hired me under the condition that I obtain my Microsoft Certified Systems Engineer (MCSE) certification within a certain amount of time. Unfortunately, MCSE training classes were completely out of the question. There was no way I would've been able to take the time off from work to attend certification classes. Furthermore, the organization I was working for had agreed to reimburse me for the cost of the certification exams once I had passed, but there was no reimbursement for the cost of the training itself.
Ultimately, I ended up purchasing several different books that prepared me to take the various exams. If memory serves me, I spent about $400 on the books. Since that time I've attended several Microsoft certification classes, and looking back, I feel as though I received almost as much knowledge from the books as I did from the certification classes. The biggest difference was that the certification classes are hands-on in nature; you learn about a particular technology by working through various hands-on labs. In contrast, the books don't really give you any hands-on experience, unless you set up some computers and work through the labs.
Most of the certification books on the market are pretty good. In fact, I've passed certification exams for products that I've never even worked with just by reading some of the certification books.
Something obvious but worth noting: When purchasing certification books, keep in mind that some are better than others. When I was studying for my MCSE exams I was initially reluctant to purchase the study guides from Microsoft Press because some of the other publishers' guides cost much less, and I was on a tight budget. For the most part, the third-party study guides were fine. However, I failed a particular exam three times even though I had memorized the corresponding book. I couldn't figure out where I was going wrong until, out of desperation, I bought the Microsoft Press study guide and discovered that the book I'd been using had omitted a lot of important information. Sometimes it pays to pay up.
One of the best ways to further your professional education is to attend various IT conferences. The presenters typically have a great deal of knowledge on the subjects they're talking about, and can often give practical advice about how to apply a particular technology to real-world situations. As great as going to conferences is, however, they can be expensive. The price of admission is usually well beyond a thousand dollars, and you also have to take travel expenses into account. But, believe it or not, there are ways to make going to conferences far less expensive.
Generally speaking, if you have an expertise that's specifically related to the conference agenda, that expertise can be your ticket into the conference. For example, I speak at several IT conferences each year. Being a speaker gets you into the conference for free. As an added bonus, you usually get paid for speaking, and the event organizers even pay for your travel expenses.
Obviously, not everybody is cut out to be a speaker. I know some very intelligent people who would rather die than have to get up on stage in front of 200 people. Fortunately, there are other techniques for getting into conferences for free. One method is to be a volunteer for the conference. Some conferences that I've attended will allow you to attend for free if you'll spend a certain number of hours answering attendees' questions on a specific topic.
Yet another way of getting into conferences for free is by being a member of the press. If you regularly contribute content to any of the better-known, technology-related Web sites or magazines, then you can often obtain press credentials for IT conferences. Not only does a press pass get you into the conference for free, it often comes with other perks such as access to media-only events and media lounges with free food and drinks.
One last strategy for attending a conference on a budget is to get an expo-only pass. Many conferences offer tickets that allow you to visit the exhibit hall but that won't allow you to attend any of the technical sessions or other conference events. Expo-only passes are almost always either free or very inexpensive -- less than a hundred dollars.
Although only visiting the exhibit hall may not sound that enticing, it may very well be worthwhile. I've had some of my toughest technical questions answered by vendors in the exhibit hall.
January 2010 — Unless you've been living under a rock for the last year, you know that the United States is in the midst of a deep recession. As such, companies are doing pretty much anything they can to cut costs. According to a lot of the people I've talked to, one of the first things to go is the IT training budget. But that doesn't mean you have to go without training: You just have to be a little bit creative.
This was something that I figured out a long time ago. In 2001 I quit my job as a CIO to become a full-time freelance writer. One of the things I quickly discovered was that the only way I could prosper was to keep my knowledge current and to learn as much as I possibly could about a wide variety of technologies. As much as I love training classes, there's no denying that they tend to be expensive and time-consuming. In my line of work, attending traditional training classes just doesn't make sense for me. Many of the classes that I'd be interested in cost about $2,000 per week. Not only would I have to pay the tuition out of my own pocket, but the time I spent in class would be better spent making money by writing articles. Fortunately, I've discovered a lot of different techniques over the years for keeping my education current without breaking the bank. Given the current state of the economy, it's an opportune time to share some of these techniques with you.
|3/17/04 - PprKuT from Jakarta says:||for partha: have you ever try to search what you looking for in kazaa or eMule???|
|3/17/04 - T-Mac from Columbus says:||Currently hold MCSE, MCP plus I, A plus, Network plus, Compaq APS -Servers, Desktops & portables. Numerous printer certs. Never failed a test. Studying for the 640-801 and finding it surprisingly difficult. It appears the failure rate is pretty high the first few times also. I have Todd Lammle's 640-507 study guide and have ben pulling stuff off the web to study. Should this do it? Or is the test really as hard as everyone says??|
|3/17/04 - alireza from iran says:||plz send to exam (640-801)|
|3/17/04 - Anonymous says:||I just took the test 640-801 today for the second time and failed with a score of 815. I had atleast 3 questions that werent in the Cisco Semester 1, 2, 3 and 4 study guide or Que Exam Cram 2 and Sybex CCNA Study Guide. I failed by 1 but no more than 2 questions or else I would have made it to the 849 mark... gooood... back to studies.|
|3/19/04 - Rajendra T from India says:||I have to give CCNA Exam. Any one guide me how to prepare for this Exam. Which study Materials is useful for passing this examination. and which topic i have to concentrate . is Techmedia books is useful Author Wendell Odom.|
|3/20/04 - Halekala from Troy, MI says:||I have taken Cisco 640-801 today for the second time and I failed both times. I ran out of time today. One simulation took nearly 10 minutes to finish. The simulator was so slow that I was pulling my hair. It was about adding networks in a RIP network. I should've read all the comments here before preparing 2nd time. Questions are definitely sneaky. Yes, you have to know subnetting pretty well. Frustrating part is that you simply don't have enough time!|
|3/21/04 - Michael from Georgia says:||Today, I took and passed the CCNA 640-801 with a score of 883. Wow, what a great feeling. On top of the world now that I have accomplished this. This was my second test and it is challenging. Definitely, you must have your act together. Study to prepare well. Subnetting, ACLS, Frame-Relay, and Switching concepts were emphasised. Prepare and you can accomplish this. Knowledge combined with test question familiarity is key to success. Good luck to all future CCNAs.|
|3/22/04 - vinodh from chennai says:||yet i have not taken exam i have a confidence so it will be easy to me my suggestion is u just take a online test daily|
|3/22/04 - Waqar AMIN from Singapore says:||I am preparing for CCNA, but after looking at comments got scared :(. Don't know how to work out. Any one suggestion for preparation books will be well come.|
|3/23/04 - MUSISI YUNUSU from UGANDA says:||plize send the new ccna exam for each semester thank u.|
When deciding which study guides will fully prepare you for the new CCNA 640-801 exam, keep in mind that while the objectives have been reorganized, the knowledge tested really hasn't changed much from the previous CCNA exam 640-607. Therefore, if you have already started your studying, continue on with your existing 607 study guides and materials. You should also pickup a router simulator or a real router to prepare for the router simulator questions. Cisco uses a router simulator in their exams developed by the Cisco Networking Academy program You can view and even demo a copy of the official Cisco exam simulator here. Many third-party offerings are very similar to this product.
That wraps it up for the version of the CCNA exam. Remember, if you still feel overwhelmed, you can now obtain this certification through a process of two exams by passing both the INTRO (640-821) and ICND (640-811) exams (both of which we'll review on this site shortly). Good luck!
Under this final heading you'll find these topics listed:
- Describe network communications using layered models.
- Describe the Spanning Tree process.
- Compare and contrast key characteristics of LAN environments.
- Evaluate the characteristics of routing protocols.
- Evaluate TCP/IP communication process and its associated protocols.
- Describe the components of network devices.
- Evaluate rules for packet control.
- Evaluate key characteristics of WANs.
Spanning tree protocol (STP) is enabled by default on all Cisco switches. Along with STA (Spanning Tree Algorithm), it avoids switched network loops. STP allows exchange of bridge protocol data units (BPDUs) by the switches to choose a Root bridge (switch, in this case) and determine where the network loops are present. Then the STA requires switches responsible for creating loops place their redundant port or ports in a blocked state preventing network loops. There are five port states possible: blocking, listening, learning, forwarding and disabled.
Tip: The listening state is where the port determines whether or not it should participate in the forwarding of frames. The learning state is when the port learns MAC addresses that are added to the forwarding database.
Remember, routers divide networks into different broadcast domains for controlling client and server network broadcast traffic. Switches and bridges create or divide collision domains.
HDLC is the default Cisco router serial interface encapsulation type and is only understood by other Cisco routers using Cisco's HDLC.
Tip: ISDN supports a faster call setup than traditional analog modems.
PPP is an authentication method; using chap is preferred since the password is never sent across the wire. The configuration command is username username password password, where username is the hostname of the peer router. Note: passwords must be identical at both ends and the hostname and password are case sensitive.
For this objective area, Cisco expects you to know how to:
- Utilize the OSI model as a guide for systematic network troubleshooting.
- Perform LAN and VLAN troubleshooting.
- Troubleshoot routing protocols.
- Troubleshoot IP addressing and host configuration.
- Troubleshoot a device as part of a working network.
- Troubleshoot an access list.
- Perform simple WAN troubleshooting.
The OSI model is a no-brainer: How could any network guru possible get through an average day without knowing the OSI model? If you're not familiar with it yet, the OSI 7-layer reference model from the top is Application, Presentation, Session, Transport, Network, Data Link and Physical layers. The numbering starts from the bottom (physical layer is number 1). Knowing the layer names and their order is crucial. Some people like to use an anagram to help. One of my favorites is (from the bottom up) Please Do Not Throw Sausage Pizza Away.
Knowing where the most common network devices operate in the OSI model is also a must. At the physical layer there is the cabling of the network, repeaters, and hubs. The data link layer includes bridges and switches, and routers operate at the network layer.
Tip: A switch is a multi-port bridge.
As a CCNA, you need to understand protocol operation and at which layer each function. This exam focuses only on TCP/IP. From the physical layer up, there are protocols, such as V.35 and RS-232, that define the physical connection and signaling on the wire. At the data link layer protocols such as Ethernet, token-ring and FDDI are responsible for defining the network topology and data communication standards .
At the network layer, there is IP, ICMP ARP. At the transport layer, there is TCP and UDP. UDP is fast and efficient but does not provide guaranteed delivery and retransmission like TCP. TCP is more commonly used at this layer by many upper-layer protocols and applications. TCP uses windowing, buffering and acknowledgments for flow control. Skipping over the session and presentation layers for brevity, the application layer contains Telnet, FTP, TFTP, SMTP, and many other application-type protocols.
Troubleshooting IP addresses, subnet masks, and gateways requires knowledge of subnetting. You may be presented with a simple network diagram consisting of subnets, routers and hosts, and be asked to identify the incorrect assignment of IP addresses. You might also find a question relating to configuration of access lists. Remember the rules from above as well as the following: If you created an access list with various deny statements and no permit, you would prohibit the routing of all traffic on the applied interface. Remember there is the explicit deny at the end of each access list.
Tip: Ping, traceroute and show ip route can be used to troubleshoot connectivity problems.
Understanding how to perform the password recovery procedure on a Cisco router is must-have knowledge for the CCNA. Remember that on the 2500 series routers, the command config-register 0x2102 returns the bits from 0x2142, which were changed in the rommon mode using the command o/r for password recovery.
This area covers the following topics:
- Configure routing protocols given user requirements.
- Configure IP addresses, subnet masks, and gateway addresses on routers and hosts.
- Configure a router for additional administrative functionality.
- Configure a switch with VLANS and inter-switch communication.
- Implement a LAN.
- Customize a switch configuration to meet specified network requirements.
- Manage system image and device configuration files.
- Perform an initial configuration on a router.
- Perform an initial configuration on a switch.
- Implement access lists.
- Implement simple WAN protocols.
Routers can be configured for network routes and discovery via routing protocols. Manually configured, connected and static routes are usually preferred since they have some of the lowest administrative distances. For the exam, remember when viewing the routing table of a Cisco router, you will see two values in brackets -- such as [100/2] -- which indicates the administrative distance and hop count or other metric. Also indicated next to each route in the table is whether it is a connected route (C), static route (S), or was learned dynamically via a routing protocol (with designations such as R for RIP and I for IGRP).
RIP and IGRP are fairly simple to configure. For RIP the IOS command would be router rip followed by the network statement. For IGRP it is router igrp 10, which includes an autonomous system number, followed by a network statement.
Tip: When an interface is configured for passive routing, the interface will accept but not advertise network routes.
Once again, this section of the exam relies heavily on your knowledge of subnetting. You may be presented with a simple network diagram consisting of subnets, routers and hosts, and be asked to identify the proper assignment of IP addresses. Read each and every address carefully as the answer may not always be obvious!
Every CCNA should understand what happens within a Cisco switch and the bridging functions of a network. You'll want to be familiar with STP (Spanning Tree Protocol), VLANs, and the switching methods cut-through and store-and-forward. Cut-through switching is a preferred method when media collisions are low and latency at the switch cannot be tolerated. Store-and-forward, on the other hand, is needed when media collisions are high and a higher latency is acceptable.
VLANs have become a popular implementation method to connect network clients and their preferred servers logically, through the switched networks, without having to connect them to the same physical switch. The network administrator generally configures vLANs within the switches. They offer levels of security and control plus limit network broadcast traffic, much like routers.
Referring back to the Cisco white paper mentioned earlier (link above), using extended access lists you can deny telnet traffic to a router's interface; for example, ip access-list 101 deny tcp any any eq telnet (don't forget to also add a permit statement such as ip access-list 101 permit ip any any or all traffic will be denied). You would then apply the access list to the filtered interface: ip access-group 101 in.
There are many things to configure to prepare an interface for a frame relay connection, and you should be intimately familiar with all of them. Memorize the different frame relay, DLCI configurations and LMI types. Frame relay encapsulation types are cisco and ietf with cisco being the default. DLCIs are locally significant and only represent the connection identifier from the router to the frame switch. LMI types are ansi, cisco and q933a. When there is a mismatch between two routers, communication will not take place.
ISDN and DDR configuration is new to the CCNA list of topics--not ISDN as a protocol, but as a complete understanding of how to configure ISDN and dial-on-demand routing (DDR). To begin with, here is a great reference for study: http://www.cisco.com/warp/public/793/access_dial/ddr_dialer_profile.html.
Be sure you understand the components and commands of a dialer profile and the order of configuration: