My Netwok Dictionary

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 »

For each VLAN to configure a DHCP server is the easiest way, but after this operation efficiency will be low, so we do not adopt this approach. In fact, we can use the three switches in the relay agent function to implement this method, the VLAN is usually divided into three operations on the switch, and the general three-layer switches have DHCP relay agent function, so that the switch can be Each VLAN interfaces on the DHCP relay function is enabled, so that when the client VLAN issued in connection with the DHCP server’s request, in the current VLAN can not be found, they will submit this information to the Interface, and then sent by the DHCP server interface, sub. By using this method, you can let the client communicate with each other with the DHCP server as the client and the DHCP servers set up by a floating bridge to send messages between the two back to normal. Please join the following essays look at the operation were how to achieve. Read the rest of this entry »

Although a firewall to prevent network intrusion has a high efficiency, and has become to the Security Web site and services are key factors, but all these security are achieved at high cost. In short, the firewall will limit the performance and scalability. Since the firewall will create a single point of failure of the line equipment, so it will reduce the availability of the network. Firewall technology and emerging Web switching technology allows the combination of firewall performance, availability and scalability are greatly improved.

The most commonly used by the installed firewall software on a server form. This server has two network cards installed, and was inserted into the data path. A network card which connects to the network’s public side, the public Internet terminal is usually connected with the router (the so-called firewall “dirty” side). Another piece of card attached with the need to protect the resources (the so-called firewall “clean” side). Read the rest of this entry »

Abstract At present the next-generation softswitch core network (NGN) for their small investment, quick, flexible configuration being carriers and product providers of all ages. The use of IP softswitch technology and the establishment of the internet network, based on its own security to the system must establish a comprehensive security mechanism. In this paper, the definition of telecommunications needs of network information security, citing the safety of the popular attacks on the basis of that system should provide security services, and focuses on the establishment of security mechanisms involved and related technologies.

I. Introduction:

The next-generation softswitch core network (NGN) operators the advantages of making investments and accelerate the reduction on the network construction progress at the same time, enabling service providers and users benefit. However, the present, although many manufacturers launched the softswitch solution, operators are also actively carry out the construction, but because of the technology and applications will make things last ten years, in perfect agreement, the business still need to be carried out long time to carry out, especially the NGN bearer network to IP network as a voice network, how to solve the existing network security systems can become safe, stable operation of the key. Read the rest of this entry »

For businesses that pocket tight, the use of asymmetric switches to improve network performance is a good choice. Such as the asymmetric switch can be used in server and client connections. Such as web Xia ago in a small business when the network administrator’s time, when the switch is a relatively expensive equipment. Enterprises have a file server, file server in order to improve the working efficiency, but, also because of funding constraints, the net asymmetry of Man is a good use of the switch, use it to improve file server access efficiency. The high speed port on the file server and the low-speed port on the client. Because when there are multiple employees simultaneous access to when the file server, requiring more bandwidth allocated to the server connected to the switch port, the port that appears to prevent traffic bottlenecks. If this is so, the connection port on the file server, there is enough bandwidth to accommodate the user’s access request, thereby improving the efficiency of employees to access the file server. Read the rest of this entry »

In the product, it will switch the second tier and third tier a combination of both routers into a switch market, the third layer switching equipment gradually become a mainstream flexible solution that provides wire-speed performance at all levels. This integrated structure also introduced a strategic management property, which not only make the second layer and third layer to associate with each other, but also provides traffic priority processing, security, and a variety of other flexible features such as link aggregation, VLAN and Intranet dynamic deployment. Meanwhile, the market for switches and higher safety performance requirements, due to network security performance requirements continue to increase, VPN technology and secure authentication technology Widely used.

Three-layer OSI model of switching equipment operating in the third layer, all the features of a traditional switch. Subject to the third layer switch, the switch of the specific technology, including: Read the rest of this entry »