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Cisco 1841 Modular Router: Q&A to Its Full Background and Features

October 19 2011 , Written by Cisco & Cisco Router, Network Switch Published on #Cisco Routers


Q. What are the Cisco 1800 Series Integrated Services Routers?

A. The Cisco 1800 Series is part of the Cisco Integrated Services Router product line. The Cisco 1800 Series consists of the Cisco 1800 Series fixed routers and the Cisco 1841 modular router.


Q. Why did Cisco Systems introduce the Cisco 1800 Series?

A. Cisco introduced the Cisco 1800 Series to allow the secure deployment of multiple, integrated services at wire-speed performance. In general, the integrated services router product line provides high performance while running simultaneous services such as data, security, and quality of service (QoS) in one integrated routing platform. The best-in-class Cisco 1800 Series architecture has been specifically designed to meet requirements of small-to-medium-sized businesses (SMBs) and small enterprise branch offices as well as service provider-managed services applications. The Cisco 1800 Series delivers secure concurrent services at wire-speed performance and allows for lower operational and capital expenditures because of the high degree of integration and ease of installation, management, and deployment.


Q. What is the Cisco 1841 Integrated Services Router?

A. The Cisco 1841 is a modular router that is designed to intelligently integrate data and security services into one single, resilient system for fast, scalable delivery of mission-critical business applications. It is specifically engineered for customers who want to securely deploy multiple, concurrent services at wire-speed performance with security and QoS features enabled. The Cisco 1841 comes in a desktop form factor with two modular WAN-interface-card (WIC) or high-speed WIC (HWIC) slots for data connectivity. It offers hardware-based encryption for Data Encryption Standard (DES), Triple DES (3DES), Advanced Encryption Standard (AES), and Secure Sockets Layer (SSL) VPN as well as Cisco IOS® Firewall and Cisco IOS Intrusion Prevention System, which can be enabled through an optional Cisco IOS Software security image. The Cisco 1841 router provides two integrated 10/100BASE-T Fast Ethernet ports onboard, an integrated USB port (1.1), as well as an internal advanced-integration-module (AIM) slot. The modular form factor of the Cisco 1841 helps ensure investment protection with WICs and HWICs that are compatible with the Cisco 2800 and Cisco 3800 Series Integrated Services Routers.


Q. With the introduction of the Cisco 1800 Series, what are the plans for the current Cisco 1700 Series Modular Access Routers?

A. The Cisco 1700 Series will reach end of sale on March 27, 2006. New feature development for the Cisco 1700 Series will be available through Cisco IOS Software Release 12.4T with bug-fix support through Cisco IOS Software Release 12.5 Mainline.


Q. Does the Cisco 1841 offer a bundled security, data, and broadband solution similar to the Cisco 1700 Series?

A. Yes. Bundled security solutions with support for hardware-based encryption for DES, 3DES, AES, SSL VPN, Cisco IOS Firewall, and Cisco IOS Intrusion Prevention System are available for the Cisco 1841. Bundled data and DSL solutions are also available for the Cisco 1841.


Q. What is the performance of the Cisco 1841?

A. The Cisco 1841 is a new-generation, best-in-class router platform designed to deliver multiple concurrent services at wire-speed performance up to single T1/E1/xDSL speeds. Chassis performance has been increased up to five-fold, and security performance increased up to seven-fold compared to the Cisco 1700 Series. The single T1/E1/xDSL value quoted here represents IMIX packet sizes in higher-than-typical Cisco 1841 services configurations. In less service-heavy environments, actual WAN throughput
will be higher.


Q. How does the Cisco 1841 router compare to the Cisco 1721 router that is the current Cisco 1700 Series data-only version?

A. The Cisco 1841 router provides significant additional value compared to the Cisco 1721 router by offering more than a five-fold performance increase. It also integrates hardware-based encryption that can be enabled with an optional Cisco IOS Software security image while simultaneously supporting multiple services such as security, data, and QoS, and providing increased slot performance and density. Also, more than 30 existing Cisco 1700 Series WICs and multiflex trunk interface cards (voice WICs [VWICs]) (for data only) are supported. Further, both of the modular slots on the Cisco 1841 router are HWIC slots that offer greater speeds and higher port density.


Note: The WIC/HWIC/VWIC (in data mode only) slots on the Cisco 1841 router do not support Cisco product-based inline power,
or Power over Ethernet (PoE). This support is offered beginning with the Cisco 2801 Integrated Services Router as part of the Cisco 2800 Series.


Q. What are the basic specifications for the Cisco 1841 router?

A. Table 1 provides the specifications for the Cisco 1841 router:


Table 1.Product Specifications

Cisco 1800 Series Features

Cisco 1841

Target deployments

Secure data

Default memory-Uses external compact and synchronous dual inline memory module (DIMM) DRAM


32 MB/128 MB compact flash

128 MB/384 MB synchronous dynamic RAM (SDRAM)

Modular HWIC slots-total

These slots can accommodate new HWICs. They also support WICs, and multiflex trunk (VWIC) cards (for Cisco 1841 router in data mode only).


Modular slots for WAN access


Modular slots for voice support

None; Cisco 1841 does not support voice termination

Fixed LAN ports with an RJ-45 port

2 Fast Ethernet (10/100)

Fixed USB port (1.1)


AIM slots (internal)


Packet-voice-DSP-module (PVDM) slots for optional PVDM and fax DSP modules (PVDM2)

None; Cisco 1841 does not support voice termination

Onboard VPN encryption acceleration-IP Security (IPSec) DES, 3DES, AES 128, AES 192, and AES 256-can be enabled through a Cisco IOS Software security image


IP BASE Cisco IOS Software feature set by default



Q. How do the Cisco 2800 Series Integrated Services Routers differ from the Cisco 1841 Integrated Services Router?

A. Cisco 2800 Series is targeted at medium-sized businesses and small to medium-sized enterprise branch offices with even higher performance and interface density requirements. Further, the Cisco 2800 Series not only offers even higher security performance and support of network modules (except the Cisco 2801) but also voice support, including the optional integration of voicemail.



Q. For what applications is the Cisco 1841 router designed?

A. The Cisco 1841 router offers a comprehensive feature set ideal for applications and solutions requiring the following:

Secure integrated services¾Using its new best-in-class, secure, high-performance architecture; the optional integration of an AIM module; a wide array of interface cards; and the rich Cisco IOS Software services capability, the Cisco 1841 router offers the ability to easily integrate the functions of standalone network appliances and components in an interface card or AIM and supports multiple services at wire-speed performance.

Secure network connectivity for data¾The Cisco 1841 router features leading advanced, integrated, end-to-end security for the delivery of converged services and applications. The integration of security functions directly onto the router provides optimal performance for security solutions such as Dynamic Multipoint VPN (DMVPN) applications, Secure Sockets Layer VPN (SSL VPN), network admission control (NAC) for antivirus defense, inline intrusion prevention, and a transparent Cisco IOS Firewall.


WICs, VWICs, and HWICs

Q. What is an HWIC slot?

A. An HWIC slot supports HWICs. It is a newly architected, high-performance version of the current WIC slot. Both modular slots on the Cisco 1841 router support HWICs. The HWIC card can offer greater speeds and higher port density than the current WIC. In addition, the HWIC slots support Cisco product-based inline power and PoE. However, PoE is not offered on the HWIC slots of the Cisco 1841 router. The HWIC slots also support most of the more-than 30 existing WICs and VWICs (on the Cisco 1841 router in data-only mode).


Q. Is online insertion and removal (OIR) supported for cards in the HWIC slots?

A. No, OIR of modules in the HWIC slots on the Cisco 1841 router is not supported.


Q. Does the Cisco 1841 router support all the current WICs?

A. Most existing modules are carried forward for the Cisco 1800 Series Integrated Services Routers. Refer to the Cisco 1841 data sheet for a detailed listing of all supported modules: http://www.cisco.com/en/US/prod/collateral/routers/ps5853/product_data_sheet0900aecd8016a59b.html


Q. Are any WICs not supported on the Cisco 1841 router?

A. Table 2 lists the WICs that are not supported on the Cisco 1800 Series and also shows the replacement WICs that provide the same or enhanced functions.


Table 2.WICs Not Supported on Cisco 1841 Router

WICs Not Supported

Replacement WICs










Two integrated Fast Ethernet 10/100BASE-T ports




WIC-2T (for higher density, consider the Cisco 2800 Series)


HWIC-8A (for higher density, consider the Cisco 2800 Series)


None; the Cisco 1841 supports Fast Ethernet 10/100BASE-T ports


Q. Does the Cisco 1841 router support all the current multitflex trunk interface cards (VWICs)?

A. Yes, the Cisco 1841 router supports only data services on all the current VWICs.


Voice Interface Cards

Q. Does the Cisco 1841 router support VICs?

A. The Cisco 1841 router does not support voice; that is, it supports no VICs. Also, none of the multiflex trunk interface cards (VWICs) in voice mode are supported on the Cisco 1841 router.


Advanced Integration Modules

Q. What is an AIM?

A. An AIM is an advanced integration module that can be plugged into the internal AIM slot of the Cisco 1841, Cisco 2600 Series,
Cisco 2800 Series, Cisco 3700 Series, and Cisco 3800 Series routers. The AIM slot provides a way of integrating additional functions and offloading processor-intensive functions from the main CPU without reducing the LAN or WAN density of the Cisco platform by otherwise occupying an external modular slot. The encryption AIM (part number AIM-VPN/BPII-PLUS) and the SSL VPN AIM (AIM-VPN/SSL-1) are currently available for use in the Cisco 1841 router.


Q. Does the Cisco 1841 router support all the current AIMs?

A. The Cisco 1841 router supports the encryption and SSLVPN AIMs (part number AIM-VPN/BPII-PLUS and AIM-VPN/SSL-1).


Note: The VPN module supported on the Cisco 1700 Series (part number MOD1700-VPN) is not supported on the Cisco 1841 router. Instead, the encryption AIM (part number AIM-VPN/BPII-PLUS) and SSL VPN AIM (part number AIM-VPN/SSL-1) are supported on the Cisco 1841 router.


Q. Are any AIMs not supported on the Cisco 1841 router?

A. Table 3 lists the AIMs that are not supported on the Cisco 1841 router.


Table 3.AIMs Not Supported on Cisco 1841 Router

Unsupported AIMs
















Q. How many internal AIM slots are available on the Cisco 1841 router?

A. The Cisco 1841 router has one internal AIM slot.

Rack-Mount Support


Q. Is the Cisco 1841 rack-mountable?

A. The Cisco 1841 is now rack-mountable. In order to enable the rack-mount functionality, the optional Cisco 1841 rack-mount kit (ACS-1841-19-RM=) needs to be used.


Q. When was the rack-mount capability introduced on the Cisco 1841?

A. All Cisco 1841 chassis shipping since Q4FY06 are rack-mountable. Cisco 1841 chassis with the following starting serial numbers have the rack-mount screw holes: FTX1009W0Z3 (United States), FCZ100812UR (Europe, Middle East, and Africa), and FHK100653JL (Asia Pacific).


Q. Are all Cisco 1841 chassis rack-mountable?

A. All Cisco 1841 chassis shipping since Q4FY06 are rack-mountable. Please refer to the serial numbers provided above to find out whether a specific chassis has the rack-mount screw holes to be rack-mountable with the optional rack-mount kit. All chassis currently shipping are rack-mountable with the optional Cisco 1841 rack-mount kit.


Universal Serial Bus

Q. What is the USB port for?

A. The Cisco 1841 router has an integrated USB port (1.1). The USB port is configurable to work with an optional USB token for secure configuration distribution and off-platform storage of VPN credentials.


Q. Can I use the USB port as a console port?

A. No, the USB port is not available for use as a console port. If your computer has only a USB interface, you need to use a USB-to-serial conversion cable to access the console port.


Power Supply

Q. What type of power supplies does the Cisco 1841 router use?

A. The Cisco 1841 router uses a universal internal standard power supply that is applicable for all countries. There are no country-specific power supplies. The AC input voltage of this universal standard power supply spans from 100 to 240V, the frequency
from 50 to 60 Hz, and the AC input current is 2.0A. The maximum power output is 50W for the Cisco 1841 router.


Q. Does the Cisco 1841 router support 802.3af PoE?

A. Support for 802.3af PoE is not available on the Cisco 1841 router.


Q. Does the Cisco 1841 router support a redundant power supply (RPS)?

A. No, the Cisco 1841 router does not support a RPS.


Q. Does the Cisco 1841 router support DC power?

A. No, the Cisco 1841 router does not support DC power. Within the integrated services router product line, DC power support starts with the Cisco 2800 Series Integrated Services Routers, specifically with the Cisco 2811.



Q. What kind of DRAM memory does the Cisco 1841 router use?

A. The Cisco 1841 router uses SDRAM. The default DRAM for the Cisco 1841 router is 128 MB, which is fixed onboard. The Cisco 1841 has a DIMM slot onboard that can be populated with additional DRAM memory.


Q. What is the default and maximum DRAM memory in the Cisco 1841 router?

A. Table 4 shows default and maximum memory of the Cisco 1841 router.


Table 4.Default and Maximum Memory


Default SDRAM Memory

Maximum SDRAM Memory

Cisco 1841

128 MB

384 MB


Q. What kind of flash memory does the Cisco 1841 router use?

A. The Cisco 1841 Router has a single, external compact flash memory. This is the only flash memory for the system and should never be removed whenever ROM Monitor (ROMMON) is being updated with a new image or configurations or when the compact flash LED light "busy" is on.


Q. What is the flash memory used for?

A. Cisco IOS Software is stored in flash memory. In addition, configuration files can be saved in flash memory. Also, flash memory allows software upgrades to be downloaded over the WAN or LAN link and to be stored in the flash memory.


Q. What is the default and maximum compact flash memory in the Cisco 1841 router?

A. Table 5 shows default and maximum compact flash memory of the Cisco 1841 router.


Table 5.Default and Maximum Compact Flash Memory


Default Compact Flash Memory

Maximum Compact Flash Memory

Cisco 1841

32 MB

128 MB


Q. What is the ROM monitor?

A. The ROM monitor is a ROM-based program that is executed upon system power-up or reset. It performs various functions, including a power-on confidence test, hardware initialization, a system boot process, system failure debug, and file system support.


Q. What is required to upgrade the ROM monitor?

A. The boot flash device on the Cisco 1841 router is a 4-MB, fixed flash device that is not field-replaceable. The ROM monitor image can be upgraded by downloading new software. The first image in ROM is a read-only image that cannot be erased. The upgrade image is a read-write image that is stored in ROM flash memory as the second image. You can configure the router to boot ROM monitor from either of the two images, primary or secondary if it exists, in the flash memory. In order to upgrade the ROM monitor on the Cisco 1841 router, you need to have a ROM monitor image available to copy from a remote server or from the external compact flash memory.


LAN Interfaces

Q. What LAN interfaces are on the Cisco 1841 router?

A. The Cisco 1841 router has two onboard Fast Ethernet autosensing interfaces that support 10- or 100-Mbps connections.

System Architecture


Q. What is new about the architecture of the Cisco 1841 router?

A. The Cisco 1800 Series with the Cisco 1841 router was designed as a high-performance routing platform to integrate and support secure, concurrent multiple services. The entire architecture provides significant performance increases over the Cisco 1700 Series as well as security through the hardware-based encryption on the motherboard that can be enabled with an optional Cisco IOS Software security software image. Combining faster discrete components such as CPU and memory with a higher bus speed and custom silicon, the Cisco 1841 router can maintain high throughput levels while running a complex set of services.


Q. Does the architectural design of the Cisco 1841 router include a real-time clock?

A. Yes. The real-time clock keeps an accurate value of date and time for applications that require an accurate time stamp such as logging, debugging, and digital certificates.



Q. What security functions are available for the Cisco 1841 router?

A. The Cisco 1841 router integrates hardware-based encryption onboard that can be enabled with an optional Cisco IOS Software security software image that not only enables the encryption (DES/3DES/AES) but also provides Cisco IOS Firewall and Cisco IOS Intrusion Prevention System support. Other standard security features supported are access control lists (ACLs); authentication, authorization, and accounting (AAA) features such as Password Authentication Protocol (PAP) and Challenge Handshake Authentication Protocol (CHAP); TACACS+, RADIUS, and token authentication; and Lock & Key. Further, NAC for antivirus defense can be enabled on the Cisco 1841 router.


Q. Can I use the Cisco 1841 router as a firewall?

A. Yes. The Cisco IOS Firewall feature set is supported in the Cisco 1841 router. This feature set includes enhanced firewall functions such as context-based access control (CBAC), which enables securing a network on a per-application basis. Additional firewall security features include Java applet blocking, denial-of-service (DoS) detection and prevention, and more advanced logging capabilities.


Q. What is the difference in features and performance between the encryption and SSL VPN AIM and the onboard cryptographic engine?

A. The IPSec and SSL VPN AIM modules (AIM-VPN-BPII-PLUS and AIM-VPN/SSL-1) offer more than double the performance of the onboard cryptographic accelerator and more than five times the number of remote VPN tunnels. The AIM modules also offer IP Payload Compression Protocol support (IPPCP Layer 3 compression) in hardware. The AIM-VPN/SSL-1 additionally supports SSL VPN in hardware with two times the number of users supported when compared to the software-based SSL encryption feature in Cisco IOS Software.


Q. What Cisco IOS Software release and feature set are needed to use Cisco IOS SSL VPN on the Cisco 1841?

A. Cisco IOS WebVPN/SSL VPN is supported starting in Cisco IOS Software Release 12.4(6)T with the Advanced Security
and higher images.


Q. What is the maximum number of SSL VPN sessions that are supported on the 1841?

A. The Cisco 1841 supports up to 25 users when using software-based SSL encryption (without the AIM-VNP/SSL-1 module)
and 50 users when using the AIM-VPN/SSL-1 module.


Q. Does the Cisco 1841 support Secure Shell (SSH) Protocol?

A. Yes. Starting with Cisco IOS Software Release 12.4(1), SSH is supported in all images with the following exceptions: IP Base without Crypto and Enterprise Base without Crypto.


Q. Does the Cisco 1841 router work with the Cisco VPN client?

A. Yes.


Q. Does the Cisco 1841 router function with Cisco Easy VPN remote client-server mode?

A. Yes. The term Easy VPN server denotes any headend model that supports the Cisco Unity® voice messaging system workgroup specification for VPN server. The term Easy VPN client denotes any customer premises equipment (CPE) that receives IPsec configuration from an Easy VPN server. The Cisco 1841 router can serve as both an Easy VPN server and an Easy VPN client.
The Cisco 1841 router can push IPsec configurations to an Easy VPN client and can receive IPsec configurations from another Easy VPN server.


Q. Can the Cisco 1841 router perform software Lempel-Ziv-Stac (LZS) compression with the AIM VPN modules?

A. The IPSec and SSL VPN AIM modules (part number AIM-VPN-BPII-PLUS and AIM-VPN/SSL-1) perform IPPCP compression at Layer 3 in hardware prior to encryption, providing compression with security.



Q. What voice features does the Cisco 1841 support?

A. The Cisco 1841 router does not support voice termination. However the Cisco 1841 supports voice over IP (VoIP) in
pass-through mode.



Q. How is the Cisco 1841 router managed?

A. Like all Cisco routers, the Cisco 1841 router can be managed with Simple Network Management Protocol (SNMP), with a Telnet session, and through a directly connected terminal or PC running terminal emulator software.


Q. Does the Cisco 1841 router support CiscoWorks Resource Manager Essentials (RME), CiscoWorks CiscoView, the CiscoWorks VPN/Security Management Solution (VMS), and the Cisco IP Solution Center (ISC)?

A. Yes, the Cisco 1841 router supports CiscoWorks RME, CiscoWorks CiscoView, CiscoWorks VMS, and the Cisco ISC.


Q. Does the Cisco Router and Security Device Manager support the Cisco 1841 router?

A. Yes, starting with Cisco Router and Security Device Manager Version 2.0.


Q. Is Cisco Voice Manager supported on the Cisco 1841 router?

A. Cisco Voice Manager is not supported on the Cisco 1841 router because this router platform does not support voice.

For more information about the Cisco 1800 Series Integrated Services Routers, visit http://www.cisco.com/go/1800 or contact your local account representative.

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How to Choose a Suitable/Right Network Switch

October 8 2011 , Written by Cisco & Cisco Router, Network Switch Published on #Cisco Routers

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.jpg


Future Growth

 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.


Port Speed

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

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.


Forwarding Rates

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.


Link Aggregation

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...


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How to Change the Password on a 3750 Switch?

October 6 2011 , Written by Cisco & Cisco Router, Network Switch Published on #Cisco Routers

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:

9600 baud

no parity

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:



dir flash:

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:

conf t

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)

write memory


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



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Cisco Wireless Points for Home, Office and larger Enterprise

September 22 2011 , Written by Cisco & Cisco Router, Network Switch Published on #Cisco Routers

“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---ValetCisco-Valet.jpeg
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 PointsWAP4410N-Wireless-N-Access-Point.jpeg
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---AironetCisco-Aironet.jpeg

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.

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What Role Does Router Play in a Network?

September 14 2011 , Written by ciscorouterswitch Published on #Cisco Routers

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.

Notes: More routers especially Cisco routers you can visit router-switch.com to see more Cisco routers and other network hardware details...

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How to Configure a Cisco Router

September 8 2011 , Written by ciscorouterswitch Published on #Cisco Routers

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.



Materials Needed: 

- Cisco router
- Ethernet cable
- terminal emulator utility like HyperTerminal


Step 1

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.


Step 2

To implement basic configuration, type at the command prompt the text 'Enter Privilege Mode' followed by the 'Router > enable' command.


Step 3

When the cursor appears; type the 'Enter Configuration Mode' and the Router# configuration terminal command.


Step 4

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.


Step 5

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.


Step 6

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 [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.


Step 7

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 [Set IP address and subnet mask]', and 'myrouter1(config-if)#no shut [Active the port]' commands.


Step 8

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.


Step 9

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.


Step 10

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.


Step 11

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.


Step 12

To finish the configuration process, the settings must be saved either by using the 'myrouter1#wr me' or 'myrouter1#copy run start' commands.


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Easy Steps to Enable Cisco Switches

August 30 2011 , Written by ciscorouterswitch Published on #Cisco Routers

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.


More tips:

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.

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Password Recovery Procedure for the Cisco 2900 Integrated Services Router

August 24 2011 , Written by ciscorouterswitch Published on #Cisco Routers

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.


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Why Should We Care about Cisco 3560-E Series Switches

August 17 2011 , Written by ciscorouterswitch Published on #Cisco Routers

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.

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Network Equipment, Basic Knowledge You Need to Get

August 9 2011 , Written by ciscorouterswitch Published on #Cisco Routers

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.


More Related:

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.

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