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Ethernet Switches and Crossover Cables

February 29 2012 , Written by Cisco & Cisco Router, Network Switch Published on #Cisco Switches - Cisco Firewall

Ethernet Switch

A switch is something that is used to turn various electronic devices on or off. However, in computer networking, a switch is used to connect multiple computers with each other. Since it is an external device it becomes part of the hardware peripherals used in the operation of a computer system. This connection is done within an existing Local Area network (LAN) only and is identical to an Ethernet hub in terms of appearance except with more intelligence. These switches not only receive data packets, but also have the ability to inspect them before passing them on to the next computer. That is, they can figure out the source, the contents of the data, and identify the destination as well. As a result of this uniqueness, it sends the data to the relevant connected system only, thereby using less bandwidth at high performance rates.ethernet-switches-copy-1.jpg

 

Ethernet Switches and Crossover Cables

The wires in a crossover cable are “crossed” so that output signals from the transmitting device are properly sent as input signals to the receiving end. An Ethernet switch can be thought of as a device that makes temporary crossover cable connections between computers that want to communicate. Just like crossover cables, switches do not suffer from collision problems.

However, it should be noted that the actual cables used are “straight through.” The crossover function is done inside of the switch.

 

Since separate wires are used for sending and receiving, switches support operation in full duplex mode. This mode allows devices to send and receive data at the same time.

 

Advantages over Hubs

As mentioned above, switches are intelligent devices that can read the data packets that pass through them. By storing each host’s MAC address and its corresponding port in a table, switches ensure that bandwidth is not wasted by intelligently directing traffic. Hubs are dumb devices that do not do any processing.

 

Unlike hubs, switches are modern, fast, and support full duplex operation. In short, they are much better.

 

...To be continued...

 

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Are You Really Clear about What Your Customers’ Need?

February 28 2012 , Written by Cisco & Cisco Router, Network Switch Published on #Networking

Are you really clear about what your customers ’need? A Cisco staff shared his experience in communicating with his customer. In fact, in a way, the same customer’s need is so different in different Cisco staff’s eyes. But the key is to point out the Cisco clients’ problems, and then pay attention to their need.

 

Cisco staff named Stephen Speirs shared his case as follows:

How a Customer Crisis Ten Years Ago Helped Me Understand the Challenges of Cloud Service Creation Today

If you are already offering cloud services from your data center, or are starting your planning to do so, there are some key initial questions I’d advise you consider.  And they’re not about the technical aspects of data center architecture!  You find yourself asking “what cloud services should we offer?” and “How do we evolve what we offer today”.  You may, post launch, also find yourself asking “Why is the take up to our cloud services not as big as we initially forecast?”  Before you say “aha - these are questions for service providers offering cloud services”.. I would argue that these questions are fundamental to enterprise and public sector organizations too -- assuming that you intend to provide cloud services to your user community that help them do their jobs.  Following one of my colleagues who blogged earlier that, with cloud services, “you need to think like a product manager”, I will assert here that there are some key lessons from product management that can help you in creating cloud services that are actually useful to your customer and/or your internal clients and stakeholders.

 

As you may have noticed from my previous blogs, I’ve worked in product management of both products and services for a while (since 1997 in fact, when I moved from software engineering into the “dark side”) …. so what lessons have I learned that may help you address the challenges of creating and defining new cloud services?

 

If you are starting a journey to cloud, offering services from your data center – either to internal stakeholders as in the case of an enterprise business, or to external customers as a service provider would do – you should find yourself asking “what cloud services should we offer?” … and if you are already offering cloud services, you may find yourself asking “why isn’t the take up to our cloud services not as big as we’d hoped?”

 

My story around this is very clearly etched in my mind: it really was a “light-bulb” moment in my product management education. I was at a meeting with a customer at their R&D labs.

It was the 4th or 5th such meeting around the product (which so happened to be an Element Management System (EMS) – a type of network management software application.  I wasn’t directly responsible for this EMS, however I had been involved in one of the early requirements meetings.   I remember watching as a senior product manager from Cisco, and a representative from the customer (who I will now call “the customer”, although later I recognized that he was only one), reviewed the Product Requirements Document (PRD) – the document that specifies exactly what the product should and should not do -- and, page by page, signed off the document as being exactly what the customer wanted.  I was relatively new to product management then, and wow, this guy was a senior product manager, this was an impressive process, we need to start doing this in my team, and this must be the way to do things .. and so on.  I was impressed!

 

And so my lessons began …. 

 

Anyway, time went on, and the product was developed and delivered, and since I was based close to the customer, I was called on to help when the product clearly wasn’t meeting the customer expectations.  Sure, there were a few quality issues after the first release or two, but these were eventually ironed out.  Yet the customer came back and reported that his operations team still weren’t using this EMS.  We went through 3 or 4 meetings, where spreadsheet after spreadsheet of feature requests was brought back to us by the customer, with the consistent message -- “if you could implement some of these features, we would use this”.  And so it went on.  And still they didn’t use the EMS.

 

Time passed and we were back at the customer labs, for another meeting.  The primary customer contact had organised for us to meet the operations manager, whose team were the target users.  The ops manager rushed in late, and what he said next really concisely communicated what he really needed: “Sorry” he said, “we’ve just lost an Internet PoP [Point of Presence, or Central Office] and our network is at risk of collapse from the sudden increase in web traffic.  I’ve only got 10 minutes to spend with you, sorry for dragging you here.  I really don’t like you guys”, he continued, “I can’t upgrade our network because of you”.

 

In one sentence, he described his problem.  And the EMS, while it satisfied many of his “requirements”, didn’t solve his main operational headache sufficiently.  The EMS did have some software download features to help with network upgrades, but they didn’t support the large scale operational procedures this customer used to upgrade their network in a robust and cost effective manner.

 

This was a key moment in my product management learning and experience – think customer problems first, requirements second -- and indeed helped my team and I re-think our approach to the market completely (and subsequently devised a multi-award winning

product for troubleshooting MPLS networks).

 

An additional aspect was the organisational divide between our main contact in the customer and the operations team. Basically these two individuals were in different groups within the customer, and to be honest, didn’t communicate very often.  So we also missed the organisational silos that can – unfortunately -- happen in large organisations.

 

This brings me to one of the fundamental lessons of product management – the “tyre swing” analogy below – which is as relevant to cloud service creation as it was to my example above.   And I’ll discuss this more in part 2 of this blog!

 

In the meantime, if you want to find out more on Cisco Data Center Services and how we can help you develop and implement your cloud computing strategy, please check out our Cisco Cloud Enablement Services - and (of course!) have a read through some of my previous blogs.

Cisco-Cloud-Enablement-Services-copy-1.jpg

 

The Tyre Swing Analogy: How Different Users Perceive Differently the Customer Needs

 

---Original blog from How a Customer Crisis Ten Years Ago Helped Me Understand the Challenges of Cloud Service Creation Today


 

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Cisco Switch Port Security ---How to Configure Switch Security?

February 27 2012 , Written by Cisco & Cisco Router, Network Switch Published on #Cisco Switches - Cisco Firewall

Conventional network security often focuses more on routers and blocking traffic from the outside. Switches are internal to the organization and designed to allow ease of connectivity, therefore only limited or no security measures are applied.

 

The following basic security features can be used to secure your switches/Cisco switches and network:

* Physically secure the device

Use secure passwords

* Enable SSH access

* Enable port security

* Disable http access

* Disable unused ports

* Disable Telnet

 

Let’s look at how to implement and configure some of the above mentioned switch security features.

Cisco-Switch-Port-Security----How-to-Configure-Swit-copy-1.jpg


 

1. How to Configure the privileged EXEC password.  

Use the enable secret command to set the password. For this activity, set the password to orbit.

SW1#configure terminal

SW1(config)#enable secret orbit

SW1(config)#

 

2. How to Configure virtual terminal (Telnet) and console passwords and require users to login.

A password should be required to access the console line.  Even the basic user EXEC mode can provide significant information to a malicious user. In addition, the VTY lines must have a password before users can access the switch remotely.

Use the following commands to secure the console and telnet:

SW1(config)#line console 0

SW1(config-line)#password cisco

SW1(config-line)#login

SW1(config-line)#line vty 0 15

SW1(config-line)#password cisco

SW1(config-line)#login

SW1(config-line)#exit

SW1(config)#

 

3. How to Configure password encryption.

At this stage, the privileged EXEC password is already encrypted. To encrypt the line passwords that you just configured, enter the service password-encryption command in global configuration mode.

SW1(config)#service password-encryption

SW1(config)#

 

4. How to Configure and test the MOTD banner.

Configure the message-of-the-day (MOTD) using Authorized Access Only as the text. Follow these guidelines:

i. The banner text is case sensitive. Make sure you do not add any spaces before or after the banner text.

 

ii. Use a delimiting character before and after the banner text to indicate where the text begins and ends. The delimiting character used in the example below is %, but you can use any character that is not used in the banner text.

 

iii. After you have configured the MOTD, log out of the switch to verify that the banner displays when you log back in.

 

SW1(config)#banner motd %Authorized Access Only%

SW1(config)#end

SW1#exit

 

5. How to Configure Port Security

Enter interface configuration mode for FastEthernet 0/11 and enable port security.

Before any other port security commands can be configured on the interface, port security must be enabled.

SW1(config-if)#interface fa0/11

SW1(config-if)#switchport port-security

* Notice that you do not have to exit back to global configuration mode before entering interface configuration mode for fa0/11.

 

6. How to configure the maximum number of MAC addresses.

To configure the port to learn only one MAC address, set the maximum to 1:

SW1(config-if)#switchport port-security maximum 1

 

7. How to configure the port to add the MAC address to the running configuration.

The MAC address learned on the port can be added to (“stuck” to) the running configuration for that port.

SW1(config-if)#switchport port-security mac-address sticky 

 

8. How to Configure the port to automatically shut down if port security is violated.

If you do not configure the following command, SW1 only logs the violation in the port security statistics but does not shut down the port.

SW1(config-if)#switchport port-security violation shutdown

Use the show-mac-address- table command to confirm that SW1 has learned the MAC address for the intended devices, in this case PC1.

SW1#show mac-address-table

Mac Address Table

-------------------------------------------

Vlan Mac Address Type Ports

---- ----------- -------- -----

20 0060.5c4b.cd22 STATIC Fa0/11

 

You can use the show port-security interface fa0/11 command to also verify a security violation with the command.

SW1#show port-security interface fa0/11

 

Port Security : Enabled

Port Status : Secure-shutdown

Violation Mode : Shutdown

Aging Time : 0 mins

Aging Type : Absolute

SecureStatic Address Aging : Disabled

Maximum MAC Addresses : 1

Total MAC Addresses : 1

Configured MAC Addresses : 1

Sticky MAC Addresses : 0

Last Source Address:Vlan : 00E0.F7B0.086E:20

Security Violation Count : 1

 

9. How to Secure Unused Ports

Disabling unused switch ports a simple method many network administrators use to help secure their network from unauthorized access. Disabling an unused port stops traffic from flowing through the port(s)

Step 1: Disable interface Fa0/10 on SW1.

Enter interface configuration mode for FastEthernet 0/17 and shut down the port.

SW1(config)#interface fa0/10

SW1(config-if)#shutdown

 

Step 2: Disable interfaces Fa0/1 to Fa0/24 on SW1

SW1(config)#interface range fa0/1-24

SW1(config-if)#shutdown

 

More Cisco switches' tutorials: http://blog.router-switch.com/category/reviews/cisco-switches/

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What Makes LAN Different from WAN?

February 24 2012 , Written by Cisco & Cisco Router, Network Switch Published on #Cisco Wireless - Cisco Wireless AP

LANs, Local Area Networks, and WANs, Wide Area Networks, were designed to allow computers to communicate with each other to share files and information.  As network requirements have continued to grow, with video becoming an extremely popular medium to transmit across a network, so too have the sophistication and speed of LAN and WAN technologies. However, both are different in their operation therefore consideration needs to be paid to different factors that help to decide if either of these are going to be used.networking-copy-1.jpg

 

Geographical coverage

A LAN (Local Area Network) covers a small area such as a University campus, a business premises, or even as small as a home network. A WAN (Wide Area Network) covers a much larger geographical scope such as a British country or an American state.  WANS are simply LANS connected together using specialised WAN hardware and WAN technologies.

 

Connectivity

To create a LAN, workstations and printers are connected to a switch using Ethernet cables.  The switch uses algorithms to detect and store details of the devices connected to the switch uses this information to channel data packets out of the correct switch port. The cables used to connect the workstations to switches can be coaxial, copper or fibre.  There is a steady increase in the uptake of fibre optic for LAN connectivity. Computer accessories such as printers can be shared by workstations in the same LAN but not on other LANs.  Each LAN in a WAN therefore will need a separate set of hardware resources.

 

A WAN is an interconnected system of LANS, therefore the WAN link is between each LAN.  To create a WAN, therefore, extra hardware such as a router is needed along with a communications link, which is provided by communication service provider.  A router is needed to route packets, delivered to the router by a switch, out of a network segment or LAN.  The communications link is used as a carrier of these data packets to the destined LAN.  The communication links used to connect two WAN points together are either a single point to point Leased Line connection or as part of shared entities packet-switching or circuit-switching.

 

However, an alternative to these cable based connections for LAN is Wifi, whilst an alternative for WAN cable technologies is Wimax.  Both are wireless based technologies.  Wireless LANs, particularly in home networks, are peer to peer.  Wireless switches and routers can be used to connect Wireless

 

Network speed

The network speed, the speed of which data packets are transported, is faster for a LAN than for a WAN.  A LAN’s maximum speed can reach up to ten gigabytes per second.  A one hundred gigabyte LAN is also in the making.  WAN spends depend on the type of WAN service being used but will never be as fast as Ethernet LANs because the sole aim of a WAN is to transfer data between one LAN to another. There is, therefore, not an urgent need for WANs to be extremely fast unlike communication requirements within a LAN.

 

The speed of a wireless LAN depends very much on the wireless LAN standard that is being used, same goes for Wireless WANs.  

 

Expansion

To add another workstation or printer to the LAN all that's needed is just a Network Interface Card.  The Ethernet cable is attached to the Network Interface Card to the port on a switch. The switch automatically picks up the address of the new workstation, therefore requiring no configuration

 

Extending a WAN to include another LAN can involve purchasing another router if present routers have no spare serial ports, with the ports requiring configuration and testing to recognise the new LAN connection.  An extra communications link also needs to be hired from the service provider. Additionally, extra investment into powerful receivers and transmitters is required if the new LAN connection is of a distance of hundreds of miles as such length can leave the connection susceptible to attenuation and noise.

 

Cost

Because of the simplicity of configuration and adding workstations to a LAN, and the hardware requirements are therefore much lower to set up a LAN, the cost of a LAN setup is much less than the cost of a WAN setup.  Routing, employed by WANs, is also more expensive than LAN switching. 

 

LANs and WANs are different technologies that are used for different purposes.  Therefore businesses need to perform in-depth network and data requirements as well as various cost analysis procedures to determine if they require a LAN or a WAN.  If a business has a single building, then a LAN would suffice.  If they have several premises across a country then it is likely that a WAN is required if they intend on transmitting data between different LANs.

 

More Related: Two Types of Networks: LANs and WANs

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Cisco Memory & Flash, Mainly Used for Cisco Router and Switch

February 23 2012 , Written by Cisco & Cisco Router, Network Switch Published on #Cisco Modules - Cisco Cables - Cisco Memory

I usually share some information and ideas about Cisco network equipments in yahoo answers, friends from different vocations can talk about Cisco products. And recently, I pay more attention to Cisco memory and flash, so I would like to share some info about Cisco memory and flash with friends who want to buy Cisco memory.

 

Firstly, let’s see some questions asked by Cisco fans in Yahoo answer

Where can i get online Cisco FLASH memory in us?”

“Where can I find Cisco Memory?”

“What type of memory for Cisco 2811 Routers? Registered or Unbuffered?”

What kind of memory does cisco 3640 router needs?

“I want to upgrade my memory router. But I didn't know which kind of memory I should buy. Mine has 64 Mb , occupied half of them. I still need to create 4 virtual serial adapters (9 already). My service provider required us to buy extra memory (256Mb)”

“What is the max memory on a Cisco 3640 Router?”

“Where can i get online Cisco FLASH memory in us?”

 

From the questions above, we generally get the points that Cisco users concerned: where to buy, the price, the type…

 

Looking for a memory upgrade for your equipment? There are some Cisco memories for Cisco router 1800/2800/3800, Cisco 1900/2900/3900, for Cisco switch 4000/4500, switch 6000/6500

 

MEM1800-128CF Details

Product Type Flash memory card

Storage Capacity 128 MB

Form Factor CompactFlash Card

Compatible Slots 1 x CompactFlash Card

 

Notes: RouterSwitch.com is a professional Cisco supplier who can provide almost all the Cisco

items for customers.

Cisco routers: Cisco 800/1800/1900/2800/2900/3800/3900/7200/7600,

Cisco switches: Cisco Catalyst 2960/3560/3750/4500/6500, etc.

Other products like Cisco Firewalls Security, Cisco IP Phones VOIP, Cisco Wireless AP, Cisco Modules & Cards, Cisco Cables Accessories, Cisco Optics Modules, Cisco Memory & Flash, and Cisco Power Supply also offered.

 

Tips: The flash memory on a router cisco is for the system image, startup config (via NVRAM emulation), VLAN and firewall configuration, and possibly a backup or alternative version of any of the above.

 

More guide: Guide: Cisco Memory Helps You Stretch IT Budget

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Greenpeace: Who is the Coolest IT Companies?

February 22 2012 , Written by Cisco & Cisco Router, Network Switch Published on #Cisco News

The latest Cool IT Leaderboard ranks 21 IT companies on their clean energy leadership potential.Cisco

 

Internet search giant Google grabbed the top spot in the latest edition of Cool IT Leaderboard released by Greenpeace.

 

The fifth edition of Cool IT Leaderboard ranked 21 IT companies on their clean energy leadership potential, willingness to embrace clean energy solutions and potential to influence energy decisions.

 

These IT companies were ranked independently and scored against a score card using a method that that measured technology, energy consumption and political advocacy.

 

Google topped the table to score 53 out of 100, and is way ahead on climate solutions and energy impacts, due to its disclosure of its energy footprint, and for providing its impressively detailed mitigation plan for achieving emissions reductions.

 

Cisco was second with a score of 49 while Ericsson and Fujitsu scored 48 each.

 

Wipro, HCL and TCS were the three Indian IT companies ranked in the report getting a score of 33, 21 and 11 respectively.

 

“Technology giants have a real opportunity to use their power and influence to change how we produce and use energy. Google tops the table because it’s putting its money where its mouth is by pumping investment into renewable energy”, said Greenpeace International IT analyst Gary Cook.

 

“The IT sector might like to consider itself forward-thinking, but it is keeping far too quiet while the dirty energy industry continues to exert undue influence on both the political process and financial markets,” he said.

 

The rapid expansion of global telecom infrastructure and data centres that power the cloud is driving significant energy demand in many sectors, much of it from dirty sources such as coal and diesel.

 

While Google ranks high on the Leaderboard due to its political advocacy and sourcing of renewable energy, Japanese telecommunications company Softbank has received the Leaderboard’s highest political advocacy score ever for its post-Fukushima Japan, demand for a rapid shift towards renewable energy and away from nuclear power.

 

Google, Cisco, and Dell all stand out for sourcing over 20 percent renewable energy globally for each company’s infrastructures.

 

Oracle received the lowest ranking overall due to failing to disclose either renewable or dirty energy use.

 

Overall, while the Greenpeace ranking found a steady increase in the quantity and strength of renewable energy solutions from many companies such as Cisco, IBM, Ericsson and Fujitsu, it also found a significant drop-off in policy advocacy leadership by IT companies.

 

“The IT industry must use its influence, innovative spirit and technological know-how to overcome the dirty energy companies who are holding on to the status quo, and holding us back from a transition to a renewable energy economy”, said Cook. “What we are seeing is a lot of talk from companies about moving toward clean energy, but so far, not much of action”.

 

Apple and Facebook, two of the sector’s most influential brands, have not been included in this year’s study.

 

Apple was not included because its efforts do not meet the Leaderboard criteria, said Greenpeace.

 

---Original News from

http://www.cxotoday.com/story/google-cisco-greenest-it-companies-greenpeace/

More Related News:Cisco, After Google, at Top of Green IT Rankings

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How to Make Crossover Network Cables?

February 20 2012 , Written by Cisco & Cisco Router, Network Switch Published on #Cisco Modules - Cisco Cables - Cisco Memory

How to properly construct a Crossover network cable? This cable can be used to directly connect two computers to each other without the use of a hub or switch. The ends on a crossover cable are different from each other, whereas a normal 'straight through' cable has identical ends. Their uses are shown in the following diagrams.network_cables.jpg

 

Typically the ports on a hub are MDIX ports. This allows the machine at the other end to utilize its MDI Port (which is what typically a NIC card uses) without the need for a crossover cable. When I say that the ports on the hub are MDIX ports, what I mean is that one of the functions of the hub is to automatically perform the crossover functions, which are required to properly align the cables with each other. When no hub or switch is used, your cable itself must physically perform these crossover functions.

 

To expand on this a little, when using a hub or switch, the Transmit wires on the workstation need to be connected to the Receive wires on the hub; likewise, the Receive wires on the hub need to be connected to the Transmit wires on the workstation. But if you remember what we stated earlier - cables which are run from PC to Hub are 'straight through' type cables. This is because the hub is providing the required crossover functions internally for you. Thus, when you connect two machines together without the use of a hub or switch, a crossover cable is required - because both 'ends' are essentially the same - a NIC Card. The crossover function must take place somewhere, and since there is no hub or switch to do it for you, the cable must.

 

Now that we know what a crossover network cable is for, let's talk for a few about types of cabling. The two most common unshielded twisted-pair (UTP) network standards are the 10 Mbit (10BASE-T Ethernet) and the 100Mbit (100BASE-TX Fast Ethernet). In order for a cable to properly support 100 Mbit transfers, it must be rated Category 5 (or CAT 5). This type of low loss extended frequency cable will support 10 Base T, 100 Base-T and the newer 100VG-AnyLAN applications. Other types of cabling include Category 3 which supports data rates up to 16 Mbps, and Category 1 which only supports speeds up to 1Mbps. The cable we are about to make is considered Category 5, and will work on both 10 Mbit and 100 Mbit systems, assuming all components used (cables and jacks) are rated for Category 5.

 

What you need

Cable - Be sure the cable(s) you are using is properly rated for CAT 5. It should state clearly on the jacket of the cable, what it is rated at. One option that you have when selecting your cable is to use a pre-made normal 'straight through' cable, and simply whack off one of the ends, and replace with a new "Crossed Over" end. For the purpose of this article, though, we aren't going to go that route. We are going to make the whole thing from scratch - using bulk CAT 5 cable.

 

Keep everything within hands reach of you...

Connectors - Crossover cables are terminated with CAT 5 RJ-45 (RJ stands for "Registered Jack") modular plugs. RJ-45 plugs are similar to those you'll see on the end of your telephone cable except they have eight versus four contacts on the end of the plug. Also, make sure the ends you select are rated for CAT 5 wiring. There are also different types of jacks which are used for different types of cabling (such as Solid Core wire). Make sure you buy the correct jacks for your cabling.

 

Crimper - You will need a modular crimping tool. My advice on what brand to get? Well, I really don't have a preference at this point, but make sure you buy a good one. If you spend about 40 to 50 bucks, you should have one that will last ya a lifetime. Spend 10 to 20 bucks, and you might be able to make a few cables with it if you're lucky. You definitely get what you pay for when it comes to crimpers!

 

Stripper - No I'm not talking about what Spot had at his bachelor party, I am talking about a tool to strip the ends off the wires you pervert! There are several specialized tools, which can be used to strip the jackets off of cabling. If you do not have access to one of these tools, cautious use of a razor blade or knife should work just fine - but keep in mind if you go the razor blade / knife route, extra special care must be used as to not damage the wires inside the jacket.

 

Cutters - You need a pair of cutters that will allow you to cut a group of cables in a straight line. It is very important that all the wires are the same lengths, and without proper cutters, this can be a difficult task.

 

Doing the deed

You now know what crossover cables are used for. You know why you need one. You also know what you need to make one, so I guess we're ready... First thing you will want to do it cut off the appropriate length of cable that you will need. Be sure that it is plenty long enough. If you screw up, and don't cut it long enough, you will have to start all over, and you will not only waste you time, but cable and the RJ-45 ends as well. If you are pulling this cable through a wall, or ceiling, make sure the pulling is completed first. It is much more difficult to pull a cable with the ends already on it. So you have all the parts, you understand the concepts, and you have your cable, lets get started!

 

Basic steps...

1) - Start by stripping off about 2 inches of the plastic jacket off the end of the cable. Be very careful at this point, as to not nick or cut into the wires, which are inside. Doing so could alter the characteristics of your cable, or even worse render is useless. Check the wires, one more time for nicks or cuts. If there are any, just whack the whole end off, and start over.

 

2) - Spread the wires apart, but be sure to hold onto the base of the jacket with your other hand. You do not want the wires to become untwisted down inside the jacket. Category 5 cable must only have 1/2 of an inch of 'untwisted' wire at the end; otherwise it will be 'out of spec'. At this point, you obviously have ALOT more than 1/2 of an inch of un-twisted wire, but don't worry - well take care of that soon enough.

 

3) - Up to this point, things have been pretty easy. Things will get a little bit tricky here, but don't worry, we'll get through this together. We are at a point in this article where a decision needs to be made. You need to decide which end of the cable you are making at this point in time. If you are making your cable from scratch like I am doing while writing this article, you have 2 end jacks, which must be installed on your cable. If you are using a pre-made cable, with one of the ends whacked off, you only have one end to install - the crossed over end. Below are two diagrams, which show how you need to arrange the cables for each type of cable end. Decide at this point which end you are making and examine the associated picture below.

 

Begin to untwist the twisted exposed wires on your cable. Use caution so that you do not untwist them down inside the jacket. Once you have all the wires untwisted begin to arrange them in the proper order based on the pictures above. This stage can be a pain in the ass, especially some of the middle wires. Once you get all the wired arranged in the proper order, make sure your wire cutters are within reach then grasp them right at the point where they enter the jacket. Make sure you keep them in the proper order! Grab your cutters now. Line them up along your prepared wires about 1/2 inch above the jacket. Be sure at this point that you are both 1/2 inch above the jacket, and that your cutters are aligned straight across the wires. You want to make a clean cut here - also make sure you don't let go of that jacket / wires!

 

4) - Don't worry. From this point forward things get a lot easier. Grab your jack, and begin to slide the wires into the jack. Once you get to the point where the jacket begins to enter the jack things might get a little tough, but just have some patience and hold onto those wires. It will fit in there just fine. Once it is in as far as it will go the wires should extend almost to the front of the jack, and about 3/8 of an inch of the jacket will be inside the jack. Like the pictures below.

 

5) - Grab those crimpers - because not all crimpers are exactly the same your pictures may not match exactly what you see below. Be sure to keep a good grip on that jack and the cable. Insert the jack into the crimper. It should only go in one way, so you don't have a whole lot to worry about inserting it. Begin to compress those crimpers. You will more than likely hear a clicking sound. Keep squeezing. If you try to let go to early, nothing will happen. They will not release. Keep going until they stop clicking / stop moving all together. At this point, you should be able to let go of the jack, and the crimpers. The crimpers should release now leaving you with a crimped jack. If the crimpers do not release, you probably are a wimp and didn't press hard enough. Go ask your mom to help you at this point. She can probably finish what you started.

 

6) - It's time to examine what we have done. If you look at the end of the jack (distal), you should see that the copper connectors should not be pressed down into the wires. Toward the back of the jack (where the jacket meets the jack) it should be crimped securely holding the jacket / cable in the jack. If something has gone wrong, don't worry, its not the end of the world. Grab those cutters, and just whack the whole jack off and start back at step 1 (a pain in the ass I know, but its better to have a cable that works, than to spend hours trouble shooting your PC trying to figure out why you can't see the other machine). If everything is cool, all you have to do now is make the other end of the cable (unless you are using a pre-fab cable and have whacked one of the ends off), so go back to step one, and make the other end now.

 

In closing

You should now have a fully functional CAT 5 Crossover cable. It's a good idea to label it as such, especially if you have a lot of other cables lying around. So what are ya waiting for... install the cable and test it out. If it doesn't work, double-check the ends. There is always a possibility that you have overlooked something. If so just whack the bad end and make new one. Remember the more jacks you install, and the more cables you make, the easier it gets. It's really not that hard to do, the first time is definitely the most difficult.

 

Here are a few other things to keep in mind...

Maximum Cable length for including connectors is 100 meters (or about 328 feet)

Do not allow the cable to be sharply bent, or kinked, at any time. This can cause permanent damage to the cables' interior

Do not overtighten cable ties

Do not use excessive force when pulling cable through floors, walls or ceilings

Do not use staples to secure category-5 cable, use the proper hangers, which can be found at most hardware stores

 

---Article resources from http://www.littlewhitedog.com/content-8.html

More Related: How to Make Your Ethernet Crossover Cable?

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Cisco: Mobile Data Traffic to Grow Eighteenfold Over 5 Years

February 18 2012 , Written by Cisco & Cisco Router, Network Switch Published on #Cisco News

Smartphones, tablets, mobile video and increasingly quick networks are growing mobile Internet traffic to incredible levels, according to a recent Cisco report. It's time to learn what a quadrillion is.

 

Mobile Internet data traffic is increasing at a rate that tests a mere mortal's math prowess. With increases in streaming content, growing connections from mobile device and machine-to-machine (M2M) modules and powerful mobile devices leading the way, Cisco Systems reports in a new Visual Networking Index Forecast that worldwide mobile data traffic is expected to increase eighteenfold over the next five years, reaching an annual run rate of 130 exabytes by 2016.

 

An exabyte equals 1 quintillion bytes. A quintillion is 10 to 18th power; it has 18 zeroes, compared with a trillion, which has 12. To get your brain around these numbers, this mobile data traffic is the equivalent of 33 billion DVDs, 4.3 quadrillion (that would be 10 to the 15th power) MP3 files or 813 quadrillion Short Message Service texts.

 

So, really a lot of traffic, then.

 

The number of connected mobile devices is expected to exceed the number of people on Earth by 2016—10 billion devices to 7.3 billion folks, according to the Feb. 14 report. Additionally, mobile cloud traffic, which currently accounts for 45 percent of mobile data traffic, is expected to grow 28 fold by 2016, accounting for a 71 percent share of traffic.

 

The increased use of smartphones and tablets, faster networks and video-rich applications is also increasingly making traffic generators of us all.

 

“By 2016, 60 percent of mobile users—3 billion people worldwide—will belong to the 'Gigabyte Club,' each generating more than 1GB of mobile data traffic per month," Suraj Shetty, Cisco's vice president of product and solutions marketing, wrote in the report. "By contrast, in 2011, only one-half percent of mobile users qualified."

 

The Index additionally forecasts:

 

• The amount of traffic added to the mobile Internet between 2015 and 2016 will be three times the estimated size of the entire mobile Internet in 2012. 

 

• Wireless devices and nodes will be the primary contributors to traffic. By 2016, there will be more than 8 billion handheld or personal mobile devices and nearly 2 billion M2M connections, including in-car GPS systems, asset-tracking systems and medical applications.

 

• By 2016, approximately 90 percent of mobile data traffic will be driven by smartphones, laptops and other portable devices.

 

• By 2016, 5 percent of mobile data traffic will be driven by M2M traffic. Another 5 percent will be driven by residential broadband mobile gateways.

 

• By 2016, 71 percent of mobile data traffic will be mobile video.

 

• Tablets alone will generate traffic that will grow by a factor of 62 by 2016, representing the highest growth rate of any device in the forecast.

 

Necessary to supporting so much traffic, said the report, will be offloading traffic to fixed/WiFi networks—something that was done with 11 percent of traffic in 2011; in itself, fixed/WiFi traffic was more than 18 times greater than cellular traffic. By 2016, 22 percent is expected to be downloaded to fixed/WiFi networks.

 

Finally, increases in traffic are also expected to drive connection speeds, as they have already; the average mobile connection speed doubled in 2011, and by 2016, it's expected to increase ninefold. Excellent news. And the average smartphone connection speed? In 2011 it was 1,344K bps. In 2012 that's expected to rise to 1,829K bps, and in 2016 to a very quick 5,244K bps.

 

More News Related: Cisco Appeals Microsoft-Skype Approval in EU

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What are Ethernet and Ethernet Switches?

February 14 2012 , Written by Cisco & Cisco Router, Network Switch Published on #Cisco Routers

Ethernet is the most common LAN (Local Area Network) technology in use today. Xerox developed Ethernet in the 1970s, and became popular after Digital Equipment Corporation and Intel joined Xerox in developing the Ethernet standard in 1980. Ethernet was officially accepted as IEEE standard 802.3 in 1985. The original Xerox Ethernet operated at 3Mbps. Ethernet networks up to 10Gbps now exist.

Erternet Switches

 

Ethernet Cabling

The first Ethernet standard, 10Base-5, ran over thick coaxial cable. A later standard, Ethernet 10Base-2, ran over a much thinner coaxial cable. These two versions of Ethernet were colloquially known as thicknet and thinnet.

 

Modern Ethernet standards run on UTP (Unshielded Twisted Pair) or fiber-optic cabling.

Ethernet Standard

Cable Specification

10Base-T

Category 3 UTP

100Base-TX

Category 5 UTP

1000Base-T

Cat 5e UTP

1000Base-SX

Optical Fiber

 

Ethernet Topologies

Ethernet 10Base-5 and 10Base-2 used a bus topology. Bus topologies were difficult to maintain and troubleshoot.

Modern Ethernet networks use a star topology with an Ethernet hub, switch, or router at the center of the star.

It is still possible to create a two-node Ethernet network in a bus topology using a null-Ethernet cable between the two devices.

 

Ethernet DTE and DCE

All nodes on an Ethernet network are either DTE (Data Terminal Equipment) or DCE (Data Communications Equipment).

Ethernet DTE are devices such as computers and printers that are trying to communicate on the Ethernet network.

Ethernet DCE are devices such as switches and routers that are trying to help other devices communicate on the Ethernet network.

 

Ethernet CSMA/CD

Like any network, Ethernet must have an algorithm for determining when each network node is allowed to communicate.

In Ethernet, this algorithm is known as CSMA/CD (Carrier Sense Multiple Access / Collision Detection).

CSMA/CD has proven to be a very capable, if highly anarchistic, algorithm.

 

Ethernet Switch

A switch is something that is used to turn various electronic devices on or off. However, in computer networking, a switch is used to connect multiple computers with each other. Since it is an external device it becomes part of the hardware peripherals used in the operation of a computer system. This connection is done within an existing Local Area network (LAN) only and is identical to an Ethernet hub in terms of appearance except with more intelligence. These switches not only receive data packets, but also have the ability to inspect them before passing them on to the next computer. That is, they can figure out the source, the contents of the data, and identify the destination as well. As a result of this uniqueness, it sends the data to the relevant connected system only, thereby using less bandwidth at high performance rates.

 

More Ethernet and Ethernet Switches Tips: Ethernet & Ethernet Switch

 

 

Ethernet Switches and Crossover Cables

The wires in a crossover cable are “crossed” so that output signals from the transmitting device are properly sent as input signals to the receiving end. An Ethernet switch can be thought of as a device that makes temporary crossover cable connections between computers that want to communicate. Just like crossover cables, switches do not suffer from collision problems.

 

However, it should be noted that the actual cables used are “straight through.” The crossover function is done inside of the switch.

 

Since separate wires are used for sending and receiving, switches support operation in full duplex mode. This mode allows devices to send and receive data at the same time.

 

Advantages over Hubs

As mentioned above, switches are intelligent devices that can read the data packets that pass through them. By storing each host’s MAC address and its corresponding port in a table, switches ensure that bandwidth is not wasted by intelligently directing traffic. Hubs are dumb devices that do not do any processing.

 

Unlike hubs, switches are modern, fast, and support full duplex operation. In short, they are much better. 

 

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Quick FAQ: CISCO CCNA Exam

February 10 2012 , Written by Cisco & Cisco Router, Network Switch Published on #Cisco Certification - CCNA - CCNP - CCIE

"The CCNA certification (Cisco Certified Network Associate) indicates a foundation in and apprentice knowledge of networking. CCNA certified professionals can install, configure, and operate LAN, WAN, and dial access services for small networks (100 nodes or fewer), including but not limited to use of these protocols: IP, IGRP, Serial, Frame Relay, IP RIP, VLANs, RIP, Ethernet, Access Lists." ---Quote from cisco.com

Cisco-CCNA-Exam--640-607-Certification-Guide.jpg

 

How many tests is the CCNA composed of?

There are two options in taking this test: The 640-801 CCNA exam, or (2) exams: 640-821 INTRO and 640-811 ICND.

 

The choice is yours to make. The 640-801 exam consists of both the objectives included in the INTRO and ICND exams.

 

Format of the Test(s)

Duration: 90 minutes

Number of Questions: 55-65

The exam questions can be in the following format:

  • Multiple Choice
  • Fill-in-the-blank
  • Drag-and-drop(drag objects in the correct order)
  • Simulated lab (actual interface into a network, troubleshooting scenario)

 

How long does the certification last for?

"CCNA certifications are valid for three years. To recertify, either pass the current CCNA exam, or pass the ICND exam, or pass any 642 professional level or Cisco Qualified Specialist exam (excluding Sales Specialist exams), or pass a CCIE written exam on or after October 1, 2004." - cisco.com

 

Retake Policy

  • After a fail, must wait 5 calendar days, beginning the day after the failed attempt, before you can retest.
  • Once passed, must wait a minimum of 180 days before taking the same exam.

 

What are the exam topics?

CCNA 640-801

Planning & Designing

   * Design a simple LAN using Cisco Technology

   * Design an IP addressing scheme to meet design requirements

   * Select an appropriate routing protocol based on user requirements

   * Design a simple internetwork using Cisco technology

   * Develop an access list to meet user specifications

   * Choose WAN services to meet customer requirements


Implementation & Operation

   * 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

 

Troubleshooting

   * 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

 

Technology

   * 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


INTRO 640-821

Design and Support

   * Use a subset of Cisco IOS commands to analyze and report network problems

   * Use embedded layer 3 through layer 7 protocols to establish, test, suspend, or disconnect connectivity to remote devices from the router console

   * Determine IP addresses

 

Implementation and Operation

   * Establish communication between a terminal device and the router IOS, and use IOS for system analysis

   * Manipulate system image and device configuration files

   * Perform an initial configuration on a router and save the resultant configuration file

   * Use commands incorporated within IOS to analyze and report network problems

   * Assign IP addresses

   * Describe and install the hardware and software required to be able to communicate via a network

   * Use embedded data link layer functionality to perform network neighbor discovery and analysis from the router

   * Use embedded layer 3 through layer 7 protocols to establish, test, suspend or disconnect connectivity to remote devices from the router console
 

  Technology

   * Demonstrate the mathematical skills required to work seamlessly with integer decimal, binary and hexadecimal numbers and simple binary logic

   * Define and describe the structure and technologies of computer networks

   * Describe the hardware and software required to be able to communicate via a network

   * Describe the physical, electrical and mechanical properties and standards associated with optical, wireless, and copper media used in networks

   * Describe the topologies and physical issues associated with cabling common LANs

   * Identify the key characteristics of common wide area networking (WAN) configurations and technologies, and differentiate between these and common LAN technologies

   * Describe the purpose and fundamental operation of the internetwork operating system (IOS)

   * Describe the role of a router in a WAN

   * Identify the major internal and external components of a router, and describe the associated functionality

   * Identify and describe the stages of the router boot-up sequence

   * Describe how the configuration register and boot system commands modify the router boot-up sequence

   * Describe the concepts associated with routing, and the different methods and protocols used to achieve it

   * Describe how an IP address is associated with a device interface, and the association between physical and employ IP addressing techniques

   * Employ IP addressing techniques

   * Compare and contrast collision and broadcast domains, and describe the process of network segmentation

   * Describe the principles and practice of switching in an Ethernet network

   * Explain how collisions are detected and handled in an Ethernet system

   * Explain the fundamental concepts associated with the Ethernet media access technique

   * Describe how the protocols associated with TCP/IP allow host communication to occur

   * Describe the operation of the Internet Control Message Protocol (ICMP) and identify the reasons, types and format of associated error and control messages

   * Describe the principles and practice of packet switching utilizing the Internet Protocol (IP)

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