The IEEE 802.16 set of standards lays down the specifications for wireless broadband technology. It has been commercialized as Worldwide Interoperability for Microwave Access (WiMAX) that is responsible for the delivery of last-mile wireless broadband access.The IEEE 802.16 MAC sublayer is the most important sublayer and concerned with channel management. It has been designed for connection-oriented channel management for point-to-multipoint (PMP) broadband services.The frame format of a generic MAC frame is shown below −The fields are −EC − A single-bit field indicating whether the payload is encrypted.Type − A 6-bit field identifying frame type.CI − A single-bit field denoting the ... Read More

A SAN is a network of storage devices that can be accessed by multiple servers or computers. It provides a shared pool of storage space. Each computer on the network can access the storage on the SAN as though they were local disks connected directly to the computer. SAN uses SCSI and SATA protocols.NAS are storage devices that are linked to a network and provide file access services to computer systems. These devices generally include an engine that executes the file services and one or more devices on which data is stored. NAS uses file access protocols such as NFS ... Read More

All these three protocols provide a mechanism for flow control. Read through this article to get a basic overview of Stop and Wait, Go-Back-N, and Selective Repeat protocols. Stop and Wait Protocol It is the most fundamental flow control strategy. The transmitter sends one frame at a time to the receiver using this method. The transmitter will come to a halt and wait for the receiver to respond. The interval between sending a message and receiving an acknowledgment is known as the sender's waiting time, and the sender is idle during this time. After receiving an acknowledgment (ACK), the ... Read More

The Windows Registry also holds information regarding recently accessed files and considerable information about user activities, besides configuration information. Hence, this article serves the purpose is to provide you with a depth understanding of the Registry and Wealth of information it holds. Today most administrators and forensic analysts, the registry probably looks like the entrance to a dark.Windows RegistryThe system was largely managed by several files-specifically, autoexec.bat, config.sys, win.ini (on windows) and system.ini. So, various settings within these files determined what programs were loaded and how the system looked and responded to user input, a central hierarchical database that maintains configuration ... Read More

Nmap is a free open source tool, employed to discover hosts and services on a computer network by sending packets and analyzing the retrieved responses. Nmap offers some features for probing computer networks, including host discovery and service and operating system detection.Nmap can provide further information on targets, including reverse DNS names, device types, and MAC addresses.Host discovery – Identifying hosts on a network. For example, listing the hosts that respond to TCP and/or ICMP requests or have a particular port open.Port scanning – Enumerating the open ports on target hosts.OS detection – Determining the operating system and hardware characteristics ... Read More

If we think an advance level of anti-virus has been installed on our computer, and we are fully secure as it performs a full system threat infection scan regularly. However, there may be instances where the scan did not detect any threat, or you cannot perform a scan. In these scenarios, we recommend that to notice the aggressive methods or symptoms to detect threats or attack.If it has been noticed an unwarranted presence of PowerShell in the task manager then our computer is definitely under attack.If a connection found to be established on port 4444 or 445 without your cognizance ... Read More

Many people are unaware, that by sending an email to others, they disclose more information about them, which they do not prefer to disclose. Yes, most of you might be surprised to know this.Whenever you send an email message to others, few unwanted information also goes along with your message, which is called header information. Header information might also disclose unwished information to recipients such as your IP address, which might be easily used by the recipients in order to find your normal location and varied private things about you.Some DifferentiatorsDepending on the email provider you use, the IP address ... Read More

This article will help us to understand the multiplex SSH sessions by setting up a master session, then having subsequent sessions by using multiplexer to speed up the SSH connection on Linux.MultiplexingMultiplexing is nothing but send more than or more over a single connection of SSH and can reuse the existing TCP/IP connection for multiple concurrent SSH connection. This will reduce the load of creating new TCP connections on the server.Advantages of Multiplexer on SSH Connection.It uses the existing *inx socket to connect.IT uses existing TCP/IP connection no more new TCP/IP.No more key exchanges.No need of authentications.Configuring MultiplexingIf the config ... Read More

This article is written to prepare high availability of a website. This can also be used by those who want their website to be available to their clients or users with high availability servers and to share between their servers. It is a free and open source application used as a TCP/HTTP load balancer which will distribute web traffic to multiple servers and improves performance and reliability of the web server.InstallationAssume that load balancer HA proxy server IP address is http://192.167.57.150HAproxy Server detailsOS: Centos 6.7, IP Address: 192.168.57.150WebServer1OS: Centos 6.7, IP Address: 192.168.57.147WebServer2OS: Centos 6.7, IP Address: 192.168.57.148We need to ... Read More

Angry IP Scanner is an open-source and cross-platform network scanner. It is very faster and simple to use platform which scans IP addresses and ports. TCP/IP(Angry IP) network scanner allows users to easily scan IP addresses within any range of your choice via a user-friendly interface. Once Angry IP Scanner detects an active IP address, then it resolves MAC address, hostname, and port/s. The gathered data information can be saved as TXT, CSV, XML or IP-Port list files. This article describes” How to install and use IP scanner in Linux”Installing Angry IP ScannerTo install Angry IP Scanner in Ubuntu/Linux Mint, ... Read More