All about Networking

Not satisfied with DNS, Microsoft invented another naming service for Windows, called WINS (Windows Internet Name Service). WINS is a Windows-specific name service for TCP/IP and is meant for networking geographically distant Windows computers (it typically isn’t used on a local area network). WINS not only maps names of servers but also maps names of workgroups and NT domains.It’s unlikely that WINS will be around in the next generation of Windows machines (although it’s still around in...

Prologue for this article. You’ve probably asked yourself in one of the preceding paragraphs, “How does www.co.chatham.ga.us get translated into 167.195.160.9?” Furthermore, why use names at all? People can deal with phone numbers, why not just use the IP number? These are good questions. The answer to the latter is that just because people can deal with a number doesn’t mean that they prefer to use a number. Which would you rather remember, 1-800-NETWORK or 1-800-638-9675? Obviously, most...

To be able to perform, find, or protect against DoS activities, you must first understand the basic principles and types of these attacks. Three main types of DoS attacks exist: Consumption of resources, such as bandwidth, hard disk space, CPU resources, and so on Disruption of configuration information, routing, DNS, and other information Direct disruption of network communication between the client and the server As information about common DoS attacks has been mentioned in many other Hacking Exposed books, we'll only briefly describe these types of DoS attacks and will then move on ...

The Internet has experienced numerous cases of DoS attacks. Unfortunately, due to the nature and existing inherited drawbacks of current Internet-centric protocols, these attacks are likely to stay with us for a long time, causing havoc and financial losses to thousands of organizations all over the world. As we have already stated, the usual cause behind the attacks from experienced Black Hat hackers is to achieve some level of remote control (be it enable or unprivileged access) over the...

As for serial links, the link layer provides data exchange between neighboring computers as well as data exchange between computers within a local network. For the link layer, the basic unit of data transfer is the data link packet frame. A data frame is composed of a header, payload, and trailer. A frame carries the destination link address, source link address, and other control information in the header. The trailer usually contains the checksum of the transported data. By using the...

The network layer ensures the data transfer between two remote computers within a particular Wide Area Network (WAN). The basic unit of transfer is a datagram that is wrapped (encapsulated) in a frame. The datagram is also composed of a header and data field. Trailers are not very common in network protocols. As shown in the figure above, the datagram header, together with data (network-layer payload), creates the payload or data field of the frame.There is usually at least one router on WANs...

A network layer facilitates the connection between two remote computers. As far as the transport layer is concerned, it acts as if there were no modems, repeaters, bridges, or routers along the way. The transport layer relies completely on the services of lower layers. It also expects that the connection between two computers has been established, and it can therefore fully dedicate its efforts to the cooperation between two distant computers. Generally, the transport layer is responsible for...

The session layer facilitates exchange of data between two applications. In other words, it serves as a checkpoint and is involved in synchronizing transactions, correctly closing files, and so on. Sharing a network disk is a good example of a session. The disk can be shared for a certain period of time, but the disk is not used for the entire time. When we need to work with a file on the network disk, a connection is established on the transport layer from the time when the file is opened to when it is closed. The session, however, exists on the session layer for the entire time the disk is being ...

This number is an exclusive number or address for all information technology devices (printers, routers, modems, et al) use which identifies and allows them the ability to communicate with each other on a computer network. There is a standard of communication, called an Internet Protocol standard (IP). In laymans terms it is the same as your home address. In order for you to receive snail mail at home the sending party must have your correct mailing address (IP address) in your town (network) or you do not receive bills, pizza coupons or your tax refund. The same is true for all equipment

The Presentation layer gets its name from its purpose: It presents data to the Application layer and is responsible for data translation and code formatting. This layer is essentially a translator and provides coding and conversion functions. A successful data-transfer technique is to adapt the data into a standard format before transmission. Computers are configured to receive this generically formatted data and then convert the data back into its native format for actual reading (for...

Now we'll talk about layer in OSI. As we know, there are 7 layer for networking that usually used. Let we mention it below. That's all layers we need to now. In this post, we will talk about the first layer, Application layer. The Application layer of the OSI model marks the spot where users actually communicate to the computer. This layer only comes into play when it’s apparent that access to the network is going to be needed soon. Take the case of Internet Explorer (IE). You could uninstall...