My Netwok Dictionary

To enable the delivery of broadcast routing updates a Frame Relay in star topology, configure the central router logically assigned interfaces. These interfaces are called subinterfaces. Subinterfaces are logical subdivisions of a physical interface. In split-horizon environments, it is possible to forward routing updates received on one subinterface through another subinterface.

In a configuration of subinterfaces, each virtual circuit can be configured as a connection point to point. This allows each subinterface acts similarly to a leased line. By using a Frame Relay interface point to point, each pair of routers is point to point on its own subnet. Read the rest of this entry »

Often invites designers and network administrators to make decisions with respect to bandwidth. A decision could be on the need to increase the size of the WAN connection to add a new database. Another decision could be if the current LAN backbone bandwidth reaches for a fluid video training program.

The answers to such problems are not always easy to find, but you can start with a simple calculation of data transfer. Using the formula transfer time = size of file / bandwidth (T = S/BW), a network administrator can estimate several of the important components of network performance. If you know the typical size of a file for a given application, the file size divided by the bandwidth of the network, we obtain an estimate of the fastest time in which you can transfer the file.

There are two important points to consider when making this calculation:

• The result is only an estimate, because the size of the file does not include the added expense for the encapsulation.
• It is likely that the result is the transfer time in the best case, since the available bandwidth is rarely the theoretical maximum for the type of network.

Read the rest of this entry »

NAT has several advantages, namely:

• Conserves legally registered addressing scheme by allowing the privatization of internal networks.
• It increases flexibility of connections to the public. You can deploy multiple sets, sets of backup and load balancing to ensure that public network connections are reliable.
• Uniform addressing scheme in the internal network and a network without private IP addresses and NAT, Public IP address change requires the renumbering of all hosts in the existing network. The cost of renumbering hosts can be high. NAT allows the existing scheme remain, while admitting a new public address system.

Read the rest of this entry »

The model of client-server computing distributes processing across multiple computers. Distributed processing allows access to remote systems to share information and network resources. In a client-server, the client and the server share or distribute the processing responsibilities.

Most network operating systems use the client-server model to provide network services to users. The computers on a network can be called hosts, workstations, clients or servers. Any computer running TCP / IP, either a workstation or server, is considered a host computer.

The following are definitions of other terms commonly used:

• Local Host: The computer that you work at that time.
• Remote Host: A system that the user has access from another system.
• Server: Provides resources to one or more clients via a network.
• Client: A computer that uses the services of one or more servers on a network.

Read the rest of this entry »

The two main classes of IGP are distance vector and link state. Both types of routing protocols seek routes through autonomous systems. Distance vector and link state routing protocols use different methods to perform the same tasks.

Algorithms link state routing, also known as algorithms Open Shortest Path First (OSPF), maintains a complex database of topology information. The routing algorithm maintains link-state full details of distant routers and interconnection.

On the other hand, the distance vector algorithms provide information not specified on distant networks and no information about remote routers. It is important to understand how routing protocols operate link state to configure, verify and troubleshoot. This module explains routing protocols, link state, describes their functions, describes the algorithm used and highlights the advantages and disadvantages of link-state routing. Read the rest of this entry »

This article explains how OSPF algorithm uses the shortest path to determine the best route to a destination. In this algorithm, the best route is the least cost. The algorithm was developed by Dijkstra, a Dutch computer specialist in 1959.

The algorithm considers the network as a set of nodes connected by point to point links. Each link has a cost. Each node has a name. Each node has a comprehensive database of all links and therefore knows the physical topology information in its entirety. All database link-state within a given area are identical. Read the rest of this entry »

This article explains the default settings of a switch and how to verify it. At first light, a switch has default data in the active configuration file. The default hostname is Switch. Not set any password on the lines of console or virtual terminal (vty).

You may be granted to the switch IP address for management purposes. This is configured in the virtual interface, VLAN 1. By default, the switch has no IP address. The switch ports or interfaces are set to automatic mode and all switch ports are in VLAN 1. VLAN 1 is known as the management VLAN by default. Read the rest of this entry »

There are some factors that make the LAN becomes congested and overloaded. LANs are increasingly congested and overburdened. Besides a large number of network users, some other factors have combined to test the capabilities of traditional LAN:

Loss of quantum: In some cases, a loss of data packets in the transmission process within a computer system. This leads to difficulties when it comes to official documents. There are several reasons for the quantum of lost data on a network - errors in the channel, the intermediate network overhead. You can also occur if someone intentionally discards traffic to enforce any particular level of service. Read the rest of this entry »

ISDN PRI interface provides leased line T1 or E1. The main tasks of PRI interface settings are as follows:

• 1. Specify the correct PRI switch type that connects to the router interface to the ISDN central provider.
• 2. Specify the T1/E1 controller, framing type and line coding equipment provider ISDN terminal.
• 3. Multiplexing Sequencing PRI interface for T1/E1 terminal equipment and indicate the speed used.

As routers are connected to the PRI through T1/E1 interfaces, there is no command “interface first”. Instead, the physical interface of the router that connects to the leased line driver called T1 or E1 controller, when using an E1 line. Read the rest of this entry »

The services actually provided to users via the Internet is not defined by the routing mechanisms of transmission control protocol/Internet protocol (TCP IP) but on the contrary, application protocols high level, for example hypertext transport protocol (HTTP), the file transfer protocol (FTP), network news transfer protocol (NNTP) and simple mail transfer protocol (SMTP).

Since these protocols are not incorporated into the Internet itself, it is possible to use a new protocol to the application layer consists only of a server to transmit the protocol data in the appropriate format and a client to receive and interpret such data. However, the usefulness of a service to users increases with the number of servers that service. Read the rest of this entry »