SONABY-TECH

       Swap space or a swap area is space on the disk drive used as overflow for parts of memory that are not currently being used. This allows the system to make room in main memory fr data currently beginning processed, and provides emergency overflow if the system is at risk of running out of space in main memory. SYSTEM RAM and Recommended Minimum Swap Space Up to 4 GB            : at least 2 GB 4 GB - 16 GB         : at least 4 GB 16 GB –  64 GB    : at least 8 GB 64 GB – 256 GB   :  at least 16 GB Creating and Using an Additional Swap Partition - Create a new partition using fdisk . Additionally, change the partition type to “ 0*82 Linux Swap” before saving changes with fdisk. - mkswap /dev/vdaN  will prepare the partition for use as a swap area. - blkid  /dev/vdan will determine the UUID. -  Add the new swap space to /etc/fstab :  UUID- uuid         swap     swap    defaults              0             0 - swapon –a will act

           VIM  ( vi improved) is a powerful text editor which is more sophisticated than gedit . Also , unlike gedit, you can always expect vim to be available in any Linux system.The vim editor supports  sophisticated text manipulation which are very useful for system administration. In fact, if you are familiar with the vi utility, you will find that vim includes vi features, plus many other features such as split screen editing , color formatting of known file types, and text highlighting for copying and changing text , to name a few. VIM Operations : - Open a file  -> vim filename - Insert mode  -> i - Return to command mode  -> Esc - To save the file -> w -  To save and quit  -> wq - Quit , abandoning changes (from ex mode)  -> q! - Undo changes  -> u - Quit file  -> q - Set the line number  ->: set nu - Unset the line number  -> set nonu - Copy  -> yy - Paste  -> p -  Delete a line  -> dd - Delete a

Netstat command                Netstat is a command line diagnostic tool which displays the information about TCP/IP  network protocol. The  basic function of netstat is to check which ports are active on the machine. It also gives information about the different ports such as the port number, the associated protocol and status. The information is helpful in getting information about which ports are closed or open and to determine which ports are vulnerable to attacks.            When you enter netstat on the command prompt , it provides you with a list of information about the connection. It also provides details such as the different protocols being used , name of your machine, TCP/IP connection, foreign address ,local address and status of connection. Ipconfig command               The basic function of Ipconfig is to display IP address , subnet mask and default gateway of each network adapter. It can also be used to display or reset the DNS cache, refresh regi

             To boot a computer is to load an OS into the computer’s memory or random access memory. Once OS system is loaded, It’s ready for users to run applications. Sometimes you will see an instruction to “reboot” the OS , This simply means to reload the OS. http://sonaby-tech.blogspot.in/ Below are the Windows XP and Windows 7 bootable files. Windows XP Boot files : NTLDR – This files helps to boot Windows XP as well as Windows 2000 BOOT.INI – It is a text file which lists the available Operating Systems found and tells the NTLDR where to find boot partition. BOOTSECT.DOS – Locates the IO.SYS file so you can start another OS in a dual boot environment. NTDETECT.COM – Loads into protected mode and detects the installed hardware on your system. NTBOOTDD.SYS – On a system with a SCSI boot device, this file is used to recognize and load the SCSI boot partition. HAL.DLL – Hardware Abstraction layer of  XP. WIN.COM – Windows XP command files. Windows 7 BOOTMGR – Found in the

                  H ere I am sharing a post about how to take system restore using system restore with command prompt . Now ,you will be having a question on your mind..  "Why system restore is so important ? " It’s the best of getting rid of virus infection, malware for computer users. Also it helps restore one’s operating system files to an earlier point time without affecting the saved personal files, such as e-mail, documents or photos. Let’s start..!! 1.        Switch on your computer. During this time keeping press on the F8 key on your keyboard till Windows Advanced Option appears, choose Safe mode with command prompt from the list and press ENTER . 2.        When command prompt mode loads enter the following line : cd restore and press ENTER . 3.        Next type this line : rstrui.exe and press ENTER 4.        Now you will be getting a System Restore Box.. Right?! 5.        Of course, Click Next . 6.        In this option you h

         Routers communicates with each other using Routing protocols. The protocols help routers to learn the network topology and changes that occur in the network topology . routing protocols use routing algorithms to decide the best output path for the received packet. Routing algorithm is a part of network layer software and should be correct, stable and simple. It should decide the perfect path for the packet depending on the network topology and traffic. For finding the best path, router considers number of hops, time delay and communication cost of the packet transmission.    A large Internet is divided into groups of networks called as Autonomous System -AS . An AS consists of network groups and routers which are managed by  a single organization. Interior routing is used within AS, whereas, Exterior routing provides routing between two ASs. Protocol Diagram :

        Routers maintain routing tables that provide information about the path from router to the destination.In Windows Operating system, there are two commands available that allow you to view the routing table.                - NETSTAT -  Allows the users to check the network configuration. It is to display protocol statistics and current TCP/IP network connections.There are several switches associated with this command.                  * Netstat - n   - Used to display all the addresses and port numbers in the form of numbers.                  * Netstat - r    -  Used to display the routing table.               - ROUTE PRINT - Allows the user to view the current routing table. This command is similar to Nestat -t      The routing table generally consist of a number of routes. Each route has information, which determines where the packed will be sent. http://sonaby-tech.blogspot.in/ Network Destination - Indicates the IP address of the outgoing packet and ref

Post Office Protocol (POP): - Best of you use only one computer to check email (Office users) - Downloads your email to the particular computer you are checking it on. - Allows you to keep a large size of email messages only limited by the size of your computer. - Does not have web interface - New messages are downloaded in their entirety ; you have to wait for the message to download. - Clients connect to email server only for the time it takes to download any new messages.  - Assumes that the currently connected client is the only client connected to the mailbox. - Simple protocol and easy to configure. - Less server loads and less costs for ISP and end users. - Searching through mailbox does not depend on mail server resources. http://sonaby-tech.blogspot.in/ Internet Message Access Protocol (IMAP):   - Best if you use many different computers to check your email (mobile users) - Your mail is al

        I n computing , a protocol is a set of rules used by computers to communicate with each other across a network. It sets a standard that controls or enables the connection, communication and data transfer between computing endpoints.   For example, HTTP and HTTPS are protocols used for communications over the Internet.  Similarly, VOIP also communicates using standard protocols and they are;   H.323 Protocols :        H.323 is an umbrella recommendation from the International Telecommunications union ( ITU ). It defines the protocols to provide audio-visual  communication sessions on any packet network. The H.323 standard address call signaling and control, multimedia transport and control and bandwidth control for point-to-point and multi-point conferences. SIP Protocols:     Session Initiation Protocol (SIP) is a signaling protocol. It is used for controlling multimedia communication sessions such as voice and video calls over IP. Other feasible applications of

              R AID in Windows 2008 is implemented not only for fault tolerance but also for improving the performance. It is a technology that provides storage functions and reliability through redundancy. Therefore, you can define RAID as group of technologies that use multiple drives, in multiple  configurations, to store redundant data.  In Windows Server 2008 , two types of RAID are implemented:                          - Software based RAID : Specifies that to implement RAID array the system processor uses special software routines. This type of RAID is usually implemented at the OS Level.                       - Hardware based RAID : Specifies that to implement RAID array controllers use proprietary disk layouts. RAID Levels :   RAID 0  (Min. 2 disks required)      Provides no fault tolerance but helps in improving performance as read and write operations occur on all drives simultaneously. However, in case of failure of one disk causes loss of data on all volum

            W indows Server 2008 also provides the wbadmin command utility to create system state backup. Perform the following steps for the system state data backup by using the webadmin command :             -  Click the Start button and then right-click Command Promt and select the Run as administrator option.    The Administrator: Command Promt appears.            -   Execute the following command:          _______________________________________________________________                        wbadmin Start SystemStateBackup -backuptarget :D:          _______________________________________________________________ In the preceding command:   wbadmin : Performs backups and restores the backed up data from the command-line with the help of batch files and scripts StartSytemStateBackup : Runs the system state backup in Windows Server 2008 -backuptarget : Specifies the backup target drive After executing the preceding command, the Do you want to start the bac

     B ackup ensures that the data of an organization is protected or can be recovered under the following circumstances :      H ardware failure      A ccidental deletion or modification of data      R estoration of the old version of a file      U nauthorized deletion or modification of data Below I mentioned the types of backups that can be performed in Windows Server 2008, Full Backup          Performs the backup of the selected files and also marks them as backed up. Full backup is usually performed when you need to take a complete backup of the system . You should select this type of backup when you are taking backup of the server for the very first time. Incremental Backup         Performs the backup of either the files marked for backup or the modified files. Incremental backup is performed in conjunction with full backup. That is , data of files from full backup is restored first and then the data of incremental backup is restored. Therefore, you should s

     The Records or Information held by Primary zone, Secondary zone and Stub zone are of various types. Some of the commonly-used record types are : Alias (CNAME) :     Refers to domain name aliases, that is , creating an alternate record or DNS name for the name already specified as another type in a particular zone. It is normally found with computers on the Internet perform multiple tasks, such as Web server and Chat server. Under such a situation, the CNAME records may be used to specify multiple names to a single computer. Host (A or AAAA records) :     Resolves an IP address to a device. The host records are essential only for the computers sharing resources on network. A records are used for IPv4 and AAAA records are used for IPv6. Mail Exchange (MX) :     Identifies mail server and routes the email messages to the specific domain. for .Example,while sending an email to abc@@sonaby.com, your mail server first looks the MX record for sonaby.com to locate the mail

pfsense is a free, open source customized distribution of FreeBSD, as a software firewall it is powerful and flexible.the current version pfsense 2.0 includes most all the features in expensive commercial firewalls, and more in many cases. The following is a list of pfsense 2.0 features. The main advantage of pfsense is we do not need to touch anything at the command line.  -Firewall - NAT (Network Address Translation) - State Table - Redundancy - Load Balancing - VPN (Virtual Private Network) - Reporting and Monitoring RRD Graphs - Real Time Info - Dynamic DNS And more....

Server 2008 Features :  Virtualization Server core IIS Role Based Installation Read Only Domain Controller - RODC Enhanced Terminal Services Network Access Protection Bit locker Windows Power Shell Better Security Cache / Proxy Management Server core Installation Server 2012 Features : IIS 8 Power shell 3.0 Direct access Cluster Shared Volumes De-duplication Hyper-V 3.0 Hyper-V Replica iSCSI NFS 4.1 SMB 3.0

Once you install the AD DS role , the files required to perform the role are installed on the server .However, in this case, the server is still not promoted to a DC, You must therefore promote the server to act as a DC by launching the Active Directory Domain Services Installed Wizard by using the dcpromo.exe command. Lets perform the following steps to promote the server to a DC and create a abc.com forest : 1. Click Start --> Run . The Run dialog box opens. 2. Type the dcpromo.exe command in the run dialog box and click the OK button.    - The Active directory Domain Services binaries start installing -  The Welcome to the Active Directory Domain Services Installation Wizard page of Active Directory Domain Services Installation Wizard appears. 3. Click the Next button.    - The Operating System Compatibility page appears. 4. Click the Next button.    - Then Choose a Deployment Configuration page appears. - 5. Select the Create Domain in a new forest radio button and click the

Active Directory Domain Services (AD DS) is a directory service from Microsoft that stores information about different network objects , such as printers ,databases and users at a centralized location and makes this information available to all the users of the network. For example :  AD DS stores data related to different user accounts , such as ids , passwords and email ids at a central location and provides secure access of these information to the authorized users. I am going to give a brief introduction to various elements of AD, such as domain controller - DC , domain , tree ,forest , trust relationship ,organizational unit - OU and site that collectively form an AD infrastructure. it also explores the forest and domain functional levels. Lets begin with a brief of the AD infrastructure. Exploring Active Directory Domain Services Some benefits of AD DS are as follows: - It follows a hierarchical organizational structure - It provides fault tolerance , which mea