Posts with #cisco routers tag
To select the appropriate switch for a layer in a particular network, you need to have specifications that detail the target traffic flows, user communities, data servers, and data storage servers. Company needs a network that can meet evolving requirements.
Traffic flow analysis is the process of measuring the bandwidth usage on a network and analysing the data for the purpose of performance tuning, capacity planning, and making hardware improvement decisions.
Network switches come in different sizes, features and functions, choosing a switch to match a particular network sometimes constitute a daunting task.
Consider what will happen if the HR or HQ department grows by five employees or more’ A solid network plan includes the rate of personnel growth over the past five years to be able to anticipate the future growth. With that in mind, you would want to purchase a switch that can accommodate more than 24 ports, such as stackable or modular switches that can scale.
When selecting a switch for the* access, **distribution, or ***core layer, consider the ability of the switch to support the port density, forwarding rates, and bandwidth aggregation requirements of your network.
Access layer switches facilitate the connection of end node devices to the network e.g. PC, Modems, IP phone, Printers etc. For this reason, they need to support features such as port security, VLANs, Fast Ethernet/Gigabit Ethernet, PoE(power over Internet, and link aggregation. Port security allows the switch to decide how many or what type of devices are permitted to connect to the switch. This is where most Cisco comes in, they all support port layer security. Most renowned network administrator knows this is the first line of defence.
Distribution Layer switches plays a very important role on the network. They collect the data from all the access layer switches and forward it to the core layer switches. Traffic that is generated at Layer 2 on a switched network needs to be managed, or segmented into VLANs, Distribution layer switches provides the inter-VLAN routing functions so that one VLAN can communicate with another on the network.
Distribution layer switches provides advanced security policies that can be applied to network traffic using Access Control Lists (ACL). This type of security allows the switch to prevent certain types of traffic and permit others. ACLs also allow you to control, which network devices can communicate on the network.
Core layer switches: These types of switches at the core layer of a topology, which is the high-speed backbone of the network and requires switches that can handle very high forwarding rates. The switch that operates in this area also needs to support link aggregation (10GbE connections which is currently the fastest available Ethernet connectivity.) to ensure adequate bandwidth coming into the core from the distribution layer switches.
Also, core layer switches support additional hardware redundancy features like redundant power supplies that can be swapped while the switch continues to operate. Because of the high workload carried by core layer switches, they tend to operate hotter than access or distribution layer switches, so they should have more sophisticated cooling options. Many true, core layer-capable switches have the ability to swap cooling fans without having to turn the switch off.
For example, it would be disruptive to shut down a switch at the core layer to change a power supply or a fan in the middle of the day when the network usage is at its Peak. To perform a hardware replacement, you could expect to have at least a 10 to 15 minute network shutdown, and that is if you are very fast at performing the maintenance. In more realistic circumstances, the switch could be down for 30 to 45 minutes or more, which most likely is not acceptable. With hot-swappable hardware, there is no downtime during switch maintenance.
Another characteristic one needs to put into consideration is port speed, which at times depend on performance requirements, choosing between fast Ethernet and Gigabit Ethernet Switch Ports.
Fast Ethernet allows up to 100 Mb/s of traffic per switch port while Gigabit Ethernet allows up to 1000 Mb/s of traffic per switch port. Fast Ethernet is adequate for IP telephony and data traffic on most business networks; however, performance is slower than Gigabit Ethernet ports..
Port density is the number of ports available on a single switch. Fixed configuration switches support up to 48 ports on a single device, with options for up to four additional ports.
High port densities allow for better use of space and power when both are in limited supply. If you have two switches that each contain 24 ports, you would be able to support up to 46 devices, because you lose at least one port per switch to connect each switch to the rest of the network. In addition, two power outlets are required. On the other hand, if you have a single 48-port switch, 47 devices can be supported, with only one port used to connect the switch to the rest of the network, and only one power outlet needed to accommodate the single switch.
Modular switches can support very high port densities through the addition of multiple switch port line cards, as shown in the figure. For example, the Cisco Catalyst 6500 switch can support in excess of 1,000 switch ports on a single device.
Switches have different processing capabilities at the rate in which they process data per second. Processing and forwarding data rates are very important when selecting a switch, the lower the processing, the slower the forwarding this results to the switch unable to accommodate full wire-speed communication across all its ports. A normal fast Ethernet port attains a 100Mb/s , while Gigabit Ethernet does 1000Mb/s.
For example, a 48-port gigabit switch operating at full wire speed generates 48 Gb/s of traffic. If the switch only supports a forwarding rate of 32 Gb/s, it cannot run at full wire speed across all ports simultaneously.
The more ports you have on a switch to support bandwidth aggregation, the more speed you have on your network traffic,. e.g. , consider a Gigabit Ethernet port, which carries up to 1 Gb/s of traffic in a network. If you have a 24-port switch, with all its ports capable of running at gigabit speeds, you could generate up to 24 Gb/s of network traffic. If the switch is connected to the rest of the network by a single network cable, it can only forward 1 Gb/s of the data to the rest of that network. Due to the contention for bandwidth, the data would forward more slowly. That results in 1 out of 24 wire speed available to each of the 24 devices connected to the switch.
Power over Ethernet (PoE)
Another characteristic you consider when choosing a switch is Power over Ethernet (PoE). This is the ability of the switch to deliver power to a device over the existing Ethernet cabling. IP phones and some wireless access points can use this feature, you can be able to install them anywhere you can run an Ethernet cable.
More tips: If you are looking for more info of Cisco switches, you can visit router-switch.com----Cisco switches: Cisco Catalyst 2960, Cisco Catalyst 3560,Cisco 3750, Cisco 4500, Cisco 6500 series, etc...
The Cisco 3750 switch has contributed greatly to Cisco's success in the networking hardware market. Its features provide efficient and reliable network switching services. You can find a pre-owned 3750 model at a good price, and if you do buy a pre-owned Cisco 3750 switch, you may need to change the password before you are able configure it to work on your network. Fortunately, Cisco has provided a built-in procedure that allows you to change the password.
Things You'll Need
Cisco 3750 switch and serial cable
Computer with terminal emulation software
How to Change the Password on a Catalyst 3750 Switch？
1. Connect your computer to the 3750 switch using the blue serial cable that typically comes with it. Connect the 9-pin d-shell connector to your computer's serial port, and connect the RJ-45 connector to the switch's console port.
2. Configure a terminal session to the switch. Power up your computer, open a terminal emulator application, and configure a terminal session with the following settings:
1 stop bit
8 data bits
Xon/Xoff flow control
Save the configuration with a name that you can recognize later.
3. Hold down the "Mode" button on the left front of the Cisco 3750 switch, and plug in the power cable. Five seconds after the Stat LED goes off, release the "Mode" button. The SYST LED should start to blink amber.
4. At the command prompt, issue the following commands to the switch to prepare it for the reset procedure, and rename the current configuration file:
rename flash:config.text flash:config.old
5. Boot the 3750 switch by issuing the "boot" command and pressing "Enter." At the "System Configuration Dialog" prompt, answer "n" and press "Enter" twice. This should display the "Switch>" prompt.
6. Issue the "en" command at the prompt, and press "Enter." You should see the prompt change from "Switch>" to "Switch#." Rename the configuration file with the following command:
rename flash:config.old flash:config.text (press "Enter")
Press "Enter" to accept the destination filename default.
7. Copy the configuration file into the 3750 memory with the following command:
copy flash:config.text system:running-config
Press "Enter" when prompted for a destination filename to accept the default.
8. eate new passwords for the 3750 switch with the following commands:
enable secret spswd (spswd = your new secret password)
enable password enpswd (enpswd = your new enable password)
line vty 0 15
password tpswd (tpswd = your new terminal password)
line con 0
password cpswd (cpswd = your new console password)
The 3750 will issue a "Building Configuration" message. When you see the [OK] message at the Sw1# prompt, you have completed the password change for the Cisco 3750 switch.
Tips: More info of Cisco 3750 switches you can visit at cisco.com
“How do I enable the wireless in a Cisco Aironet access point?” “What is the best way to setup a wireless network with several access points to give uninterrupted connectivity?” “Resetting a Cisco wireless AP 350? I found an old Cisco wireless access point (Aironet 350 AP352E2C) and was wondering how I can reset it?”
---From Yahoo Answers
Are you also looking to set up an easily accessible wireless network at home or the office? Indeed, wireless access is a great choice for easy, convenient internet and network access from anywhere you need it. And different products can allow you to extend the wireless range to just your apartment, your office building, or your entire campus. Cisco has a variety of products designed to fit every wireless requirement that you could need.
Further info on wireless access points for home, small business, and large enterprises as follows
Cisco Wireless Access Points for Home---Valet
The Valet series is made with the home in mind. Valet products are inexpensive, sleekly designed, and they’re very easy to set up. They also function as your home’s router, allowing you to connect all computers (wireless or corded) to the internet. With the Valet, you can connect your house’s bluetooth or wireless-enabled game systems or other devices with no effort at all. The included Cisco software makes the Valet easy to install and customize on any PC.
Cisco Wireless for the Office---Small Business Access Points
Cisco small business wireless access points, designed with a business owner in mind, allow you to connect farther, faster, and safer than ever before, and the more important is providing a big payoff for small business’ dollar.
The extended range of the small business WAP4410N wireless access point allows employees and guests to connect to the internet anywhere within a large range of connectivity. You can connect a variety of wireless devices in seconds to the network, and you do not even need an available outlet to connect the access point to power. These wireless access points support power-over-ethernet devices, so you can install them quickly and easily anywhere you like.
The small business series has advanced security features to protect your network from unauthorized gateways into your network. They also offer support for the fastest speeds possible with their expanded range, ensuring that your wireless users have all the performance they need right at their fingertips.
Wireless Access Points for Larger Enterprises---Aironet
The Aironet series is designed to fit in perfectly with an enterprise environment and provides sleek, rugged, and powerful performance for an extended range of use and easy scalability. The Aironets also support power-over-ethernet, this greatly lessens the difficulty of installation. Its high-capacity performance can handle large amounts of users while still offering security that large operations need to protect their network. They are also built with clean-air technology and an energy-efficient construction that will help your business reduce its carbon footprint.
For supporting a large user base, covering an extended range, and standing up to rugged environments, large businesses or institutional facilities should consider the Aironet series of wireless access points to give them the performance they need.
That’s it for this guide to Cisco wireless access points. Whether you are at home or small, medium or larger office, going wireless can greatly increase your productivity and ease of access for all your wireless devices.
The Internet is formed by networks throughout the world interconnecting and passing on data to each other. Routers make the Internet work by forwarding data using a unified addressing system. They can send information to anywhere in the world as long as that location has an IP address.
Routers vary inside to large expensive machines for commercial applications to small wireless boxes for the home electronics market. A router combines dedicated hardware and specialist software to achieve its task. To be effective, a router needs to be connected to at least two separate networks because its main task is to forward data from one network to another.
Look at the following figure, it directly display the relationship between computers and router
What is Router Used for?
Routers rely on the Internet Protocol to provide a common addressing system. The protocol defines an address structure which is universally implemented and is enforced by one controlling authority in each country. The IP address of any computer contactable over the Internet has to be unique. The computer sending information over the Internet has to package that data into a packet. The data packet contains a header which includes the IP address of the destination computer. Routers read this address and then forward the packet in the direction of its destination.
A router prepares for its work by compiling a list of possible routes to a particular destination. The format of the table does not require that every IP address is listed. They can be noted in groups. When a router is first installed it contacts its neighboring routers. These are the routers to which it is immediately connected. Each of these neighbors send their routing tables to the new router which then compiles its own routing table. Routers regularly exchange their routing tables and so information about routes held on one router eventually ripples through to all routers in the world.
The routing table contains several different paths to the same destination. The router uses an algorithm to rank these alternatives. There are many different routing algorithms in the world, but they generally all rely on the direction and the distance travelled to reach the target. The distance is often recorded as the number of links the route crosses. The direction tells the router which of its immediate neighbors starts that route.
Although the routing table contains alternative routes it does not list the routers in the path of that route, only the first router in the chain. The next router receiving the data packet then makes a calculation to decide which of its neighbors will receive the packet next, and so on. This distributed decision making allows routes to be switched in case of broken connections further down the line of which the originating router is unaware.
How to connect a router to computers
1. Ensure that both computers have a LAN (or an Ethernet) card allowing the sharing of files and peripherals. Though all new computers and laptops are equipped with such cards, you may need to buy and attach LAN cards for older models. (A network card is a devised either installed inside a desktop computer or a card that slides into a laptop. A router is the piece that will allow you to receive wireless internet and networking from the devise with the network card installed.)
2. Connect the cable from your Internet Service Provider (ISP) to the Internet port of your router. Note that if you have an ADSL connection, your input cable would be a telephone line that needs to be inserted into the ADSL port of the router. For all other connections, you would have a thicker cable known as CAT5 (or CAT6).
3. Take two Ethernet cables and plug them into the Ethernet ports of the router. Note that you will require a router with at least two Ethernet ports to share Internet on two computers. Plug the other end of each of the cables into the Ethernet port of the computers. If you have a router with a single Ethernet port, buy a network switch or hub and connect the router with it (using the Ethernet cable). In turn, the switch (or hub) that includes at least two Ethernet ports will have to be connected to the computers. (More info of switch, hub and router you can visit “Identifying What is Router, Switch and Hub”)
4. Switch on the router and the computers.
5. Configure the router by referring to its user manual. The configuration process defers depending on the type and brand of the router. Once configured, you should be able to access Internet on both computers.
The process of configuring a Cisco brand router involves the invoking of the User, Privilege, Configuration, Interface, and Line modes. These various modes are utilized to allow the definition of information relative to the password, hostname, IP address along with the subnet mask, clock rate, and line configurations that will dictate the behavior of the router device. Prior to powering up the router to undertake its configuration, it is necessary to first set up a terminal emulation application to 9600 baud with eight data bits, no parity and single bit stop. This process will also be used to define the type of protocol that will be implemented across the network which will be supported by the router that will be connected to the computer system’s serial port.
- Cisco router
- Ethernet cable
- terminal emulator utility like HyperTerminal
The initial steps to the configuration process after setting up the terminal emulation program is to power up the Cisco router and wait for the message prompt to be displayed.
To implement basic configuration, type at the command prompt the text 'Enter Privilege Mode' followed by the 'Router > enable' command.
When the cursor appears; type the 'Enter Configuration Mode' and the Router# configuration terminal command.
In order to implement password protection when accessing Privilege Mode, the 'Router(config)# enable password p@ssw0rd' and the 'Router(config)#enable secret s3cr3t' commands must be issued.
The 'Router(config)#hostname myrouter1 [Set the hostname to myrouter1]' instruction provides the user with a way of defining the Hostname or the Router Name that will be broadcasted across the network.
The commands to configure the Ethernet port consists of the 'myrouter1(config)# inte f0/0 [Enter Ethernet Interface Mode ( f0/0 for interface1, f0/1 for interface 2)]', 'myrouter1(config-if)# ip add 192.168.0.1 255.255.255.0 [Set IP address and subnet mask]', and 'myrouter1(config-if)#no shut [Active the port]' commands. These commands will allow the smooth flow of network traffic on the defined communication portals.
Configuration of the Serial Port makes use of the 'myrouter1(config-if)#inte s 0/0/0 [Enter Serial Interface Mode]', 'myrouter1(config-if)#ip add 192.168.20.1 255.255.255.0 [Set IP address and subnet mask]', and 'myrouter1(config-if)#no shut [Active the port]' commands.
It is also necessary to set the bandwidth that will be used by the router. This is commonly done by using the 'myrouter1(config-if)#clock rate 1000000 [Set the bandwidth to 1Gig]' and 'myrouter1(config-if)#exit' commands.
The Secure Console is defined by using the 'myrouter1(config)#line con 0', 'myrouter1(config-line)#password c0ns0l3', 'myrouter1(config-line)#login', and 'myrouter1(config-line)#exit' commands. These instructions will configure the access credentials that will be used to bring up this utility.
The auxiliary password that will be used to connect any modem device to the router hardware via the remote connection console may be done by using the 'myrouter1(config)#line aux0', 'myrouter1(config-line)#password auXo', 'myrouter1(config-line)#login', and 'myrouter1(config-line)#exit' instructions.
Securing the login process via SSH or Telnet processes is done by using Virtual Terminal Password. The commands 'myrouter1(config)#line vty 0 4', 'myrouter1(config-line)#password v1rtu@1', 'myrouter1(config-line)#login', 'myrouter1(config-line)#exit', and 'myrouter1(config)#exit' are executed within the Secure VTY line utility.
To finish the configuration process, the settings must be saved either by using the 'myrouter1#wr me' or 'myrouter1#copy run start' commands.
Cisco switches are network devices used on data networks to facilitate data transport. For a Cisco switch to be integrated into a network, it must be enabled before custom network configurations can be made. To enable a switch for network use, the switch will need to be named and secured with a privilege execution mode and console password.
Things You'll Need
Cisco Catalyst 2960 switch or other Cisco switch capable of IOS command line configuration (Cisco 2940, 2950, 2955 and others), Computer monitor
How to Enable Cisco Switches
1. Start the Cisco switch. Be sure that your monitor terminal is interactive with the switch so that you will be able to see the Cisco IOS command-line interface appear on start-up and configure the switch. Once started, the "Switch>" prompt will appear in the command-line interface.
2. Configure the switch with the host name network1switch. At the "Switch>" prompt in the IOS command line, type "enable," then press "Enter." The "Switch" prompt will appear. Type "#config terminal" and press "Enter." The "Switch (config)" prompt will appear. Type "#hostname network1switch" and press "Enter." The switch is now named "network1switch" and the next prompt will now read "network1switch (config)."
3. Set the privilege execution (exec) mode password to 123catalyst. At the "network1switch (config)" prompt, type "# enable password 123catalyst" and press "Enter." The privilege exec mode password is now 123catalyst. The next prompt will read "network1switch (config)."
4. Set the console password to 123cisco. At the "network1switch (config)" prompt, type "#line console 0" and press "Enter." The "network1switch (config-line)" prompt will appear. Type "#password 123cisco" and press "Enter." The console password is now set to 123cisco and the next prompt will read "network1switch (config-line)."
5. Configure the console line to require a password at log in. At the "network1switch (config-line)" type "#login" and press "Enter." The switch console line will now require a password at log in. The next prompt will be "network1switch (config-line)."
6. End the command-line configuration session. At the "network1switch (config-line)" prompt, type "#end" and press "Enter." The command-line interface session will now end. The new Cisco switch is now named network1switch with a privilege exec mode password of 123catalyst. This switch is further secured by requiring a console password of 123cisco at log in. This switch is now ready for further interface configuration and customization for your network.
Many Cisco switches require users to use the Cisco IOS command-line interface for device configuration. Familiarity and confidence with working in a command-line environment will enhance an administrator's ability and productivity when configuring many Cisco network devices.
Perform these steps in order to recover your password:
1. Either switch off or shut down the router.
2. Remove the compact flash that is on the rear of the router. This image shows the rear of the Cisco 2951 router:
For more information, refer to Back Panel Slots and Connectors on the Cisco 2921 and 2951 Routers.
3. Switch on the router.
4. Once the Cisco router is on Rommon mode, reinsert the compact flash.
5. Type confreg 0x2142 at the rommon 1> prompt in order to boot from Flash.
This step bypasses the startup configuration where the passwords are stored.
6. Type reset at the rommon 2> prompt.
The router reboots, but ignores the saved configuration.
7. Type no after each setup question, or press Ctrl-C in order to skip the initial setup procedure.
8. Type enable at the Router> prompt.
You are in enable mode and should see the Router# prompt.
9. Type configure memory or copy startup-config running-config in order to copy the nonvolatile RAM (NVRAM) into memory.
Warning: Do not enter copy running-config startup-config or write. These commands erase your startup configuration.
10. Issue the show running-config command.
The show running-config command shows the configuration of the router. In this configuration, the shutdown command appears under all interfaces, which indicates all interfaces are currently shut down. In addition, the passwords (enable password, enable secret, vty, and console passwords) are in either an encrypted or unencrypted format. You can reuse unencrypted passwords. You must change encrypted passwords to a new password.
11. Type configure terminal.
The hostname(config)# prompt appears.
12. Type enable secret <password> in order to change the enable secret password. For example:
13. hostname(config)#enable secret cisco
14. Issue the no shutdown command on every interface that you use.
If you issue a show ip interface brief command, every interface that you want to use should display up up.
15. Type config-register <configuration_register_setting> . Where <configuration_register_setting> is either the value you recorded in step 2 or 0x2102 . For example:
16. hostname(config)#config-register 0x2102
17. Press Ctrl-z or end in order to leave the configuration mode.
The hostname# prompt appears.
18. Type write memory or copy running-config startup-config in order to commit the changes.
Demands on IT infrastructure are changing. Improving network efficiency and articulating the clear value network infrastructure brings to your business have never been more important. The Cisco Catalyst 3560-E Series access and aggregation switches offer networking solutions that can expand with your business without costly upgrades or network disruptions, maximize your network investment, and decrease network costs over time.
Increased desktop bandwidth, expanded use of real-time communication and collaboration applications, and the desire to maximize networking investments are changing the way network solutions are designed and implemented. Supporting Gigabit Ethernet to the desktop often requires 10 Gigabit Ethernet connections between the access and aggregation layers to be able to maintain a quality experience for users.
These deployments can sometimes face space constraints. Voice-over-IP (VoIP) phones, security cameras, and other devices are requiring Power over Ethernet (PoE) support in networking devices. Purchasing a network solution today that grows with your business and network needs can help ensure your company’s competitiveness and success for tomorrow.
10 Gigabit Ethernet Uplinks and the Cisco TwinGig Small Form-Factor Pluggable Converter
The Cisco Catalyst 3560-E features wire-speed 10 Gigabit Ethernet uplink ports for high-bandwidth applications, relieving congestion and helping ensure smooth delivery of data. The TwinGig converter (see Figure 2) converts a 10 Gigabit Ethernet X2 interface into two Gigabit Ethernet Small Form-Factor Pluggable (SFP) ports.
Power over Ethernet
The Cisco Catalyst 3560-E Series can provide a lower total cost of ownership for deployments that incorporate Cisco IP phones, Cisco Aironet wireless LAN (WLAN) access points, or any IEEE 802.3af-compliant end device. PoE removes the need for wall power to each PoE-enabled device and eliminates the cost for additional electrical cabling and circuits that would otherwise be necessary in IP phone and WLAN deployments. With the introduction of Enhanced Power over Ethernet the 3560-E Series can scale beyond 15.4W per port delivering maximum solution simplicity for 802.11n access point deployments.
Redundant Power System
The Cisco Catalyst 3560-E Series Switches support the Cisco Redundant Power System 2300 (Cisco RPS 2300). The Cisco RPS 2300 (Figure 3) increases availability in a converged data, voice, and video network by providing transparent power backup to two of six attached Cisco Catalyst 3560-E switches at the same time. A power supply can be replaced while the switch is being powered by the Cisco RPS 2300.
Cisco Catalyst 3560-E Series Switches
Cisco Catalyst 3560-E Series Switches are an enterprise-class line of standalone access and aggregation switches that facilitate the deployment of secure converged applications while maximizing investment protection for evolving network and application requirements. Configurations for the Cisco Catalyst 3560-E access switches include 24 and 48 ports of 10/100/1000 Ethernet with dual 10 Gigabit Ethernet ports. Power over Ethernet is available on both the 24-port and 48-port models and can deliver IEEE 802.3af 15.4W class 3 PoE on all ports simultaneously. Combining 10/100/1000 and PoE configurations with 10 Gigabit Ethernet uplinks, the Cisco Catalyst 3560-E enhances worker productivity by enabling applications such as IP telephony, wireless, and video.
The Cisco Catalyst 3560-E Series aggregation solutions - the Cisco Catalyst 3560E-12D, a 12-port 10 Gigabit Ethernet aggregation switch, and the Cisco Catalyst 3560E-12SD, a 12-port SFP Gigabit Ethernet aggregation switch with 2 10 Gigabit Ethernet uplink ports, deliver secure nonstop unified network services and versatile connectivity in a one-rack unit (1-RU) form factor for space- and power-constrained environments, enabling businesses to reduce total cost of ownership while maximizing investment protection.
Cisco Catalyst 3560-E Series highlights:
• Cisco TwinGig converter module for migrating uplinks from Gigabit Ethernet to 10 Gigabit Ethernet
• PoE configurations with 15.4W of PoE on all 48 ports
• Industry first portfolio to scale beyond 15.4W per port delivering maximum solution simplicity for 802.11n access point deployments
• Access switch models have modular power supply with externally available backup
• Dual redundant modular power supplies and fans for Cisco Catalyst 3560E-12D and Cisco Catalyst 3560E-12SD aggregation switches for nonstop operation
• Multicast routing, IPv6 routing, and access control list (ACL) in hardware
• Out-of-band Ethernet management port along with RS-232 console port
Benefits of the Cisco Catalyst 3560-E
Scale your network as your business grows: With the TwinGig converter module, you can convert the 10 Gigabit Ethernet interfaces into dual SFP ports in the access and aggregation layers, allowing you to migrate from Gigabit to 10 Gigabit Ethernet when your business demands change without changing network devices. The Cisco Catalyst 3560E-12D also enables the aggregation of up to 12 10 Gigabit Ethernet links within a compact 1-RU form factor in space-constrained environments. Decrease network costs over time: the Cisco Catalyst 3560-E delivers full PoE (15.4W) on every 10/100/1000 port so that as your needs for PoE and Gigabit Ethernet grow, you are positioned to support them without costly upgrades or complete network replacements.
Computer networking devices are units that mediate data in a computer network. Computer networking devices are also called network equipment, Intermediate Systems (IS) or InterWorking Unit (IWU). Units which are the last receiver or generate data are called hosts or data terminal equipment.
The Internet has truly revolutionized the way we communicate. If you actually think about it, the Internet is computer networking at the highest scale of complexity. It’s a continuous link of connected computers that spreads worldwide. How is data transfer and the implementation of networking protocols made possible in this colossal network? It is made possible because of networking devices that regulate data traffic over the whole network, providing connectivity and control. The network design is based on the OSI (Open Systems Interconnection) model. Router, switch, hub and bridge are networking devices that act as mediators at various levels of this networking model.
What are the differences in the design and functioning of these networking devices: router, switch, hub and bridge?
Every one of these network devices which we compare in the following is a part of every Large Area Network (LAN), Wide Area Network (WAN) or small private networks. They integrate and connect the network at various levels, while providing control over data flow.
The main differences in functionality of Router, Switch, Hub and Bridge
A computer network connected to the Internet is designed to be a self-regulating network that can guarantee the transmission of data to right destinations and regulate overall data transfer. The network can be primarily divided into two types of devices which are terminals (connected computers) and control elements or connecting devices. The role router, switch, hub and bridge play in a computing network determines their basic functionality and difference.
Two or more computing networks are connected together by a router. It is charged with the responsibility of controlling the inter network data traffic. They are highly intelligent devices with embedded software that are used to control the flow of data packets across diverse networks.
A network switch is charged with the job of connecting smaller segments of a single network into a connected whole. They are extensively used in Ethernet local area networks.
A hub connects various Ethernet devices to integrate them into a whole network segment. It is one of the most basic hardware devices that connect two or more Ethernet terminals in a network.
A network bridge is nothing more than a type of switch. While a switch has multiple connection ports, a bridge has a single connection port. In the next section, let us have a look at the features of each one of these devices in more detail.
Referring to OSI model layers, a router is functional on the network layer of the OSI model, which is also known as level 3. They integrate logical subnet together and their operation is made possible by inbuilt operating systems. They are designed to calculate the best possible path for transmission of data packets between networks. The basis for routing of data through a router is the use of Internet protocol addresses. You might want to check out the OSI model diagram to understand the functions of these devices better.
Network switches are functional on the layer 2 of the OSI model. This layer is often referred to as the data link layer. Network switches transfer data across a network segment using MAC addresses for reference.
A hub operates only at layer 1 level of OSI model, which is the physical layer. Integrating Ethernet terminals together is its only function and it is a passive device used for data transfer. A bridge is just a type of network switch that connects two network segments together. Like switches, they too operate at the data link layer.
All these networking devices provide connectivity and help regulate Internet traffic through local and global Internet networks. Tips of identifying what are main networking hardware help you know the role and function of router, switch, hub and bridge in a network. So which network equipment you select depends on what you need in your home network or business network.
Common basic networking devices:
Router: a specialized network device that determines the next network point to which it can forward a data packet towards the destination of the packet. Unlike a gateway, it cannot interface different protocols. Works on OSI layer 3.
Bridge: a device that connects multiple network segments along the data link layer. Works on OSI layer 2.
Switch: a device that allocates traffic from one network segment to certain lines (intended destination(s)) which connect the segment to another network segment. So unlike a hub a switch splits the network traffic and sends it to different destinations rather than to all systems on the network. Works on OSI layer 2.
Hub: connects multiple Ethernet segments together making them act as a single segment. When using a hub, every attached all the objects, compared to switches, which provide a dedicated connection between individual nodes. Works on OSI layer 1.
Repeater: device to amplify or regenerate digital signals received while sending them from one part of a network into another. Works on OSI layer 1.
Some hybrid network devices:
Multilayer Switch: a switch which, in addition to switching on OSI layer 2, provides functionality at higher protocol layers.
Protocol Converter: a hardware device that converts between two different types of transmissions, such as asynchronous and synchronous transmissions.
Bridge Router (B router): CombineS router and bridge functionality and are therefore working on OSI layers 2 and 3.
Hardware or software components that typically sit on the connection point of different networks, e.g. between an internal network and an external network:
Proxy: computer network service which allows clients to make indirect network connections to other network services
Firewall: a piece of hardware or software put on the network to prevent some communications forbidden by the network policy
Network Address Translator: network service provide as hardware or software that converts internal to external network addresses and vice versa
Other hardware for establishing networks or dial-up connections:
Multiplexer: device that combines several electrical signals into a single signal
Network Card: a piece of computer hardware to allow the attached computer to communicate by network
Modem: device that modulates an analog "carrier" signal (such as sound), to encode digital information, and that also demodulates such a carrier signal to decode the transmitted information, as a computer communicating with another computer over the telephone network
ISDN terminal adapter (TA): a specialized gateway for ISDN
Line Driver: a device to increase transmission distance by amplifying the signal. Base-band networks only.
Dell Inc.’s deal on Wednesday to buy Force10 Networks will give the world's second-largest computer maker inroads into Cisco Systems Inc.’s turf -- networking.
Force10 is a data center networking company that makes Ethernet switchers and routers, and focuses on serving booming social media companies like Facebook and Zynga as well as giants like Google Inc.
With the acquisition of Force10 at an undisclosed price, Dell is creating a more serious competitor to Cisco, adding to the networking giant's troubles.
Cisco is already facing intense competition from smaller networking companies like Juniper Networks Inc., Check Point Software Technologies, F5 Networks Inc. and Riverbed Technology Inc.
Cisco's switching business has seen sales fall in recent quarters, and analysts have argued the company has stretched itself too thin by making several large acquisitions in the consumer market, causing it to lose focus of its core switching and routing businesses.
Force10, which generated about $50 million in revenue in the first quarter of 2011, has an edge over competitors.
Cisco, Juniper and Brocade Communications Systems Inc. all provide switching and routing technology, although very few like Force10 have the technological capability that creates the backbone of the major data centers, sources said.
The deal also means that Dell is no longer interested in buying networking equipment supplier Brocade, whose market capitalization is $2.8 billion, sources said. Dell was reported to be eyeing Brocade as well.
Over the past three years Dell has expanded its enterprise portfolio through acquisitions to include server and storage services.
In May, Dave Johnson, Dell's senior vice president of corporate strategy, told Reuters that it will continue to seek companies with valuations in the $1 billion to $5 billion range.
Dell was advised by Evercore Partners on the Force10 deal. The transaction was the first for technology investment banker Eric Mandl at his new firm. Tor Braham, head of technology M&A at Deutsche Bank, led the deal for Force10.
SALE VERSUS IPO
Force10's decision to sell to Dell is the latest in a string of private technology companies in the sector that are opting to sell rather than go public, as tech giants looking to build a broader suite of services swoop in with rich offers.
Force10 had filed its initial public offering with the Securities and Exchange Commission last year.
But in 2011, the company started discussions with a few interested parties over a sale, one source said.
Other companies that have in recent months opted to sell rather than go public include Internet video conferencing service Skype, which sold to Microsoft Corp for $8.5 billion, and Web hosting company Go Daddy which sold itself to a private equity consortium led by KKR and Silver Lake this month for $2.25 billion.