My Netwok Dictionary

It is possible that a switch is already preconfigured and only be made to passwords for user EXEC mode or privileged EXEC. You enter the configuration mode switch from the privileged EXEC mode.

In the CLI, the EXEC mode privileged default indicator is Switch #. In EXEC mode user indicator is Switch >.

The following steps will enable a completely new configuration overwrites the current configuration:

• To delete the current VLAN information, delete the file from the VLAN database, called vlan.dat flash directory.
• Erase the backup configuration file named startup-config.
• Reset the switch using the reload command.

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This article explains how bridges and switches learn addresses and send the frames. Bridges and switches need send only frames that travel from one LAN segment to another. To accomplish this task, these must learn which devices are connected to which segment of the LAN.

It is believed that a bridge is an intelligent device because it can make decisions based on MAC addresses. To do so, a bridge is consulting a table of addresses. When a bridge is turned on, messages are sent in broadcast stations asking all the local segment of the network to respond. As the answer stations broadcast the message, the bridge will create a table of local addresses. This process is called learning. Read the rest of this entry »

The routers must be configured to identify the type of switch which communicates. ISDN switch types available vary in part according to the country that uses the switch. As a result of the various implementations of Q.931, the signaling protocol used in the D channel ISDN switches varies between suppliers.

The services offered by ISDN providers vary considerably from one country to another and from one region to another. As modems, each type of switch operates slightly differently and has a specific set of requirements for the establishment of the call. Before you connect the router to the ISDN service must be configured for the type of switch. This information must be specified when configuring the router so that it can communicate with the switch, connect the call at the ISDN network and send data. Read the rest of this entry »

The construction of a LAN that meets the needs of medium and large organizations is much more likely to be successful if you use a hierarchical design model. This article discusses the three layers of hierarchical design model:

• The access layer provides workgroup users access the network.
• The layer of distribution offers policy-based connectivity.
• The core layer provides optimal transport between sites. The core layer is sometimes called a backbone.

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Functions of Layer 2 switches:

A switch is a device that connects LAN segments using a MAC address table to determine the segment to which a frame must be transmitted. Switches and bridges operate at Layer 2 of the OSI model.

Sometimes the switches are referred to as multi port bridges or switching hubs. The switches make decisions based on MAC addresses and therefore are Layer 2 devices. On the other hand, hubs regenerate the signal on Layer 1 and sent to all ports without making a decision. Read the rest of this entry »

This article describes three methods of data used in a network. The most common form of communication is done by unicast transmission. In a unicast transmission, a transmitter tries to communicate with a receiver. Another way to communicate is called multicast transmission. Multicast transmission occurs when a transmitter is communicating with only a subset or segment group.

The last form of communication is sent in broadcast. The broadcast transmission occurs when a transmitter is to communicate with all receivers in the network. The server station sends a message and all found in the segment receive the message. Read the rest of this entry »

How to switch a frame to its destination port is a tradeoff between latency and reliability. A switch can start transferring the plot as soon as it receives the destination MAC address. Switching at this point is called failover cutting method and results in lower latency at the switch. However, you can check for errors. At the other end, the switch can receive the entire frame before sending it to the destination port.

It gives the switch software can control the frame check sequence (Frame Check Sequence, FCS) to ensure that the plot has been so reliable before it is sent to the destination. If it is discovered that the frame is invalid, it is discarded in this switch rather than at the final destination. Since the whole plot is stored before being sent, this mode is called warehousing and shipping. Read the rest of this entry »

For any type of switch or hub, you must follow the instructions.

Turn on the hardware box, and confirm its contents conform to the packaging. On the stack or the switch installed in the bracket (the proper use of rubber mats or frame), its location and any device connected to 10BaseT distance of not more than 100 meters, the temperature must be suitable for products, and maintain adequate ventilation.

When selecting cable, use any port through the cable, it had no marked “X” mark. X on behalf of a crossover cable. Type 5 cable is suitable for all ports, 100BaseFX port, except it needs to fiber media. Make sure the power outlet voltage and the voltage indicated on the label is the same, and connect power. Read the rest of this entry »

In the past decade, various organizations have been keen to cut costs through simplified management, compliance and promote green IT objectives to enhance enterprise IT systems. This led to devices overwhelmed, and the original distribution of business-critical content and applications in various branches began to focus on at least end the number of core data center. At the same time, the mobile office and remote wireless endpoints gradually increased the number of users; distributed business model has been popular. This change led to a series of new generation of accelerated programs, including help users to maximize performance, and long-distance and cross the WAN to improve end-user access to critical business applications and Web experiences. Read the rest of this entry »

Work in the LAN environment, network virus attacks always hit the inevitable, once the network of workstations infected with the virus accidentally, then it can not normally access the Internet; addition, the user free to change if the IP address, the LAN IP on the vulnerable address conflict symptoms, in the event of such symptoms, workstations, Internet access will not work. Internet access in order to control the stability of this case is now proceeding from the actual combat, clever use of units of three switches in the LAN DHCP relay agent function, to let the workstation IP address from ARP virus and frequent conflicts fault! Read the rest of this entry »