Linux and networking

SNMP (Simple Network Management Protocol) is an internet protocol used in network management systems to monitor network-attached devices such as computers, servers, routers, switches, gateways, wireless access points, VoIP phones, and etc. for conditions that warrant administrative attention. SNMP provides management data in the form of variables on the managed systems, which describe the system configuration parameter or current status value. These variables can then be read and queried (or sometimes set or write) by managing applications. Windows system running XP, Vista or 2003 does not turn on SNMP service by default, thus users need to manually install and enable SNMP service.Note that you must be logged on as an administrator or a member of the Administrators group in order to complete this procedure. If your computer is connected to a network, network policy settings may also prevent you from completing this procedure. How to Install and Enable the SNMP Service In Windows XP a

1.Viruses Are Few and Far Between Although it is possible to create a virus to target Linux systems, the design of the system itself makes it very difficult to become infected. A single user could cause local damage to his or her files by running a virus on his or her system; however, this would be an isolated instance rather than something could spread out of control. 2.Open SourceAll source code is freely accessible; there are no secrets, no proprietary ties, no license fees 3.Transparent With Linux, you can always find out what the system is doing, and why. All configuration files are in plain text. Linux will do what you ask it for, no more, no less. It doesn't do magic stuff behind your back 4.Stable Linux is stable. It normally doesn't crash. A Linux server can be up for hundreds of days 5.Interoperability More and more computers are being connected to networks. No system would be complete if it did not include tools to allow it to interoperate w

CCNA admin interview questions Networking interview questions 1.You need to retrieve a file from the file server for your word processing application, which layer of the OSI model is responsible for this function? 1.Presentation layer 2.Application layer 3.Session layer 4.Transport layer 5.Datalink layer 2.You are working in a word processing program, which is run from the file server. Your data comes back to you in an unintelligible manner. Which layer of the OSI model would you investigate? 1.Application layer 2.Presentation layer 3.Session layer 4.Network layer 5.Datalink layer 3.The IEEE subdivided the datalink layer to provide for environments that need connectionless or connection-oriented services. What are the two layers called? 1.Physical 2.MAC 3.LLC 4.Session 5.IP 4.You are working with graphic translations. Which layer of the OSI model is responsible for code formatting and conversion and graphic standards. 1.Network lay

Boot sequence summary When a PC is booted it starts running a BIOS program which is a memory resident program on an EEPROM integrated circuit. The BIOS program will eventually try to read the first sector on a booting media such as a hard or floppy drive. The boot sector contains a small program that the BIOS will load and attempt to pass run control to. This program will attempt to read the operating system from the disk and run it. LILO is the program that Linux systems typically use to give users a choice of operating systems to run. It is usually installed in the boot sector which is also called the master boot record. If the user chooses to boot Linux, LILO will attempt to load the Linux kernel causing the following basic events to happen: BIOS Load boot sector from one of: • Floppy • CDROM • Hard drive The boot order can be changed from within the BIOS. BIOS setup can be entered by pressing a key during bootup. The exact key depends varies, but is often one of D

Introduction The File Transfer Protocol (FTP) is used as one of the most common means of copying files between servers over the Internet. Most web based download sites use the built in FTP capabilities of web browsers and therefore most server oriented operating systems usually include an FTP server application as part of the software suite. Linux is no exception. This chapter will show you how to convert your Linux box into an FTP server using the default Very Secure FTP Daemon (VSFTPD) package included in Fedora. FTP Overview FTP relies on a pair of TCP ports to get the job done. It operates in two connection channels as I'll explain: FTP Control Channel, TCP Port 21: All commands you send and the ftp server's responses to those commands will go over the control connection, but any data sent back (such as "ls" directory lists or actual file data in either direction) will go over the data connection. FTP Data Channel, TCP Port 20: This port is used for all subs

You might remember when you installed Linux that the installation process prompted you for a list of partitions and the sizes of each in which your filesystems would be placed. When allocating disk space for the partitions, the first sector, or data unit, for each partition is always reserved for programmable code used in booting. The very first sector of the hard disk is reserved for the same purpose and is called the master boot record (MBR). When booting from a hard disk, the PC system BIOS loads and executes the boot loader code in the MBR. The MBR then needs to know which partitions on the disk have boot loader code specific to their operating systems in their boot sectors and then attempts to boot one of them. Fedora Linux is supplied with the GRUB boot loader which is fairly sophisticated and therefore cannot entirely fit in the 512 bytes of the MBR. The GRUB MBR boot loader merely searches for a special boot partition and loads a second stage boot loader. This then reads