The micro-course contains a description of the FreeRadius system, its installation and configuration. It is the most popular free RADIUS server in the Linux system used in many implementations of IT systems for computer networks.
Keywords: freeradius, huntgroups, radiusd.conf, clients.conf, radiusd
Micro-course generally discusses the dynamic routing protocols, their advantages and disadvantages. Autonomous System concept is introduced. The reader finds out what lies at the root of the Internet, what determines which path the traffic is transmitted through. We try to explain "why sometimes packages from London to Manchester go through Frankfurt."
Fibre optics have already entered into the thatch. There is a number of ISPs that offer access to their resources through the installation of fiber optic connections at home. Fiber optic technology is present in LAN, MAN and WAN. We discuss in this course such issues as: The principle of operation of the optical fiber systems, Multi-mode and single mode systems Construction of fiber-optic connection systems (POP) and fiber panels. We present the most popular fiber connectors. Ethernet 100 Mbps, 1,10,40 and 100 Gbps technologies are discussed, which use optical paths for data transmission. Elements of the design and installation of fiber optic networks are also provided. This course is required for installers of structured cabling systems, and is part of a series of design practical micro-courses.
In this micro-course it was described how to manage packets in Debian and Ubuntu distributions.
Introduction to the operation of the IMAP protocol, the one which enables remote management of inbox. We discuss how the e-mail directories are managed, how to synchronize e-mails on the local computer and the remote inbox. A sample client and IMAP server session communication is shown.
The micro-course describes the procedure of installing and configuring the GrSecurity mechanism. It introduces a lot of protection in the Linux system kernel. The example protection is the possibility to create access lists based on Role-Based Access Control (RBAC), the possibility to impose additional restrictions on the chroot environment, the possibility to switch on the event registration mode or using random numbers for IP source ports and the PID process identifiers.
Keywords: grsecurity, paxctl, pspax. scanelf, dumpelf, execstack, paxtest, paxtest, gradm, RBAC, pollicy
Micro-course describes the family of DSL transmission technology which is mainly used to connect customers to the Internet using a modem. The course presents DSL starting from the description of the operation, the introduction of the basic concepts, to the demonstration of the advantages and disadvantages of the major protocols of this family: - ADSL (Asymmetric DSL full rate), - RADSL (Rate Adaptive DSL), - SDSL (Symmetric DSL), HDSL (High data rate DSL), - VDSL (Very high bit rate DSL), - IDSL (Integrated Services Digital Network DSL). The second part presents the Frame Relay technology, which is used to connect WAN network to local area network (LAN) or to connect LAN to the Internet. The course begins with explanation of the principles and introduces the basic concepts that are specific for Frame Relay. The mechanisms operating in the network are presented in relation to the structure of the FR frame. The course deals also with types of signaling in the FR networks and mechanism to communicate the status of a virtual circuit as well as FR transmission parameters such as guaranteed bandwidth.
The Linux distribution, as well as the kernel, can be adjusted to needs. Thanks to the fact that it is a system with GPL there is a possibility to compile a kernel optimized according to specific tasks. For example, for the built-in systems the kernel must be the smallest possible. For the counting systems the kernel is to use the server hardware architecture in the most efficient way. Apart from so specific situations in the administrator's practice the modules supporting specific hardware (e.g. hardware RAID) happen not to be contained in the kernel. In this situation it is necessary to compile the module to the kernel.
The importance of the DNS server is known to every person using its resources such as electronic mail or WWW. The micro-course discusses the way of installing and configuring the ISC BIND server, the way of creating zones and entries in the base for particular domain records.
Keywords: BIND, named, named.conf, zone
The micro-course presents configuration and administration of a few popular servers of POP - POPA3D, Solid-POP3D and Cyrus POP3D. Moreover, it describes a few popular mechanisms of supporting mailboxes such as mpop, fetchmail or fakepop.
Keywords: pop3d, solid-pop3d, cyrus pop3d, mpop, fetchmail, mpop, fakepop, POP, POP3
The process of installing and configuring the Debian distribution is presented here, step by step. Starting from partitioning, configuring the time zone up to setting up passwords. As a result, you will get ready to use operating system.
A description of the network layer monitoring on the basis of the Netflow system. The micro-course describes how to create procedures of collecting network statistics, what the Netflow protocol is, what its versions are and where they are used. Moreover, simple tools used for monitoring network interfaces were described.
Keywords: iptraf, stark, etherape bmon, iptotal, netflow, ipfix, frame, netflow v5, próbnik NetFlow, OAM, OAM&P
We live our lives in Internet era - it's a fact. Shopping, payments and money management are all subjects of online transactions too. Consequently it is necessary to ensure the safety of online transactions. That's what SSL protocol does. SSL is the main topic discussed in this micro course. Additionally, the course shows an example of configuring Stunnel package, which is used to secure any communictaion service with an encrypted SSL channel.
DHCP is currently the most widely protocol used for dynamic assigning the workstation settings like the IP address, subnet mask, gateway, DNS server addresses, domain name, etc. In this micro-course we discuss the basics of DHCP. We show how to run a DHCP server and also we mention the safety aspects of the services.
Description of SMTP, the main protocol by which email messages are sent between the client and the server and between servers. Session of communication between two devices is shown. How to verify the server? All these issues can be found in the micro-course.
The introduction of general concepts for understanding the structure of Linux. There are some definitions which the administrator uses to describe the system and the problems encountered. In almost non-technical way, the basic concepts are explained, such as the kernel or command interpreter.
This micro-course describes basic elements used by the system kernel in order to organize the system work. In this material you can find information about what the process is, how it communicates with processes, and how communication between two processes works.
The micro-course discusses configuration of the Apache server, httpd.conf and htaccess configuration files. It describes the most important commands of the configuration file and their meaning and examples. If you want to implement the WWW server in your own company, this micro-course is necessary to do this task quickly.
Keywords: httpd.conf, htaccess, DirectoryRoot
Most administrators are used to a raw text mode where the menu is displayed by writing a line with an option choice under the cursor. Introducing the ncurses library in the Linux system enables creation of smart and full-screen applications in the text mode which work is much nicer with. The basic program supporting controls and graphic elements in the text mode is the dialog command which was described in detail in this micro-course.
This micro-course describes configuration of the mail system based on the Sendmail server. It is one of the oldest implementations of the SMTP server in Linux/Unix systems. This system became a prototype for other solutions of this type.
Keywords: semdmail, mail, SMTP
The process of installing and configuring the Slackware distribution is presented here, step by step. Starting from partitioning, configuring the time zone up to setting up passwords. As a result, you will get ready to use operating system.
The Micro-course contains basic information enabling creation of a basic script.
The micro-course describes the most popular server of HTTP which is the free Apache server. It shows the history of the system, the architecture of the server work, and the way to install it. The micro-course is necessary if you want to implement the WWW server.
Keywords: apache, httpd, httpd.conf
The micro-course describes the most popular in the Linux system way of supporting resources shared in the Microsoft Windows network. This possibility is provided by the Samba program packet. It enables both sharing data contained in the Linux system partition with work stations with Microsoft Windows systems and their support of printers supported by Linux servers. Another function is the support of authorization for Linux users on the basis of data contained in the Active Directory system.
Keywords: SAMBA, smbd, CIFS, SMB, samba-tools, smb.conf
The micro-course describes the way of starting the system using a network and the PXE mechanism. This system is used for building diskless working stations which are downloaded from the net by all necessary files.
Keywords: PXE, boot, netboot, tftp
Rich support of protocols and cryptographic algorithms in the Linux system enabled creation of many tools using them. Some of the most popular tools are programs for encoding disks or partitions. In this micro-course there are the main procedures of encoding disks and partitions used in administrating this operating system.
This micro-course gives basic information on the ways of creating encoded connections and technologies used for this purpose such as IpSec or OpenVPN.
Keywords: vpnc, Cisco VPN, klient Cisco VPN, ipsec, openssl, OpenVPN
The micro-course shows the way of using the iproute2 packet in the Linux system. It is a modern approach to the network management mechanism in new Linux system kernels. Thanks to this packet the kernel does not have to be limited only to one routing table. From the ip application level you can manage the Ethernet, IP or the TCP layers.
Keywords: ip, ip addr, ip route, ip link, ip neigh, ip rule
Documentation vanished and the server should be extended. How should you check what is inside the box? What hardware is being used? The micro-course presents information usually contained in most frequently used files with information about the system status from the /proc directory. There are short descriptions of logs saved by the Linux kernel while booting. There is a presentation of a very useful interface to the DMI (Desktop Management Interface) system allowing to check the model of the motherboard or the RAM chipset producer. And the best of all are the programs for testing efficiency of hard drives.
The Micro-course describes the way of detecting hardware from the level of the Linux operating system. It discusses the main files where this information is saved on the system start as well as commands enabling collection of such information. An example of such a command is the discussed in the micro-course hwinfo command.
The administrator of the Linux system to make work easier often creates their own script whose role is automating tasks. However, the script without variables would only be an ordinary sequence of commands without a possibility to steer them. This micro-course describes the basics of how to use variables as well as replace them with values and how to delete them.
The Awk program is most often used as a line filter, yet thanks to adding a function to it you can create advanced programs not necessarily playing the role of the filter.
It seems that the topic of sleeping, or system hybernating, does not concern server installations and a serious administrator can omit it. However, the serious administrator certainly has their own work station and it is often a laptop, naturally with the installed Linux therefore the knowledge about putting the system to sleep will be very useful. As for the server environments – currently it is popular to limit the use of energy by server sub-systems. On big server farms the limit of used power by 10% is calculated to hard cash from savings which the administrator can (and even should) get a bonus from. This is exactly the subject that ACPI deals with.
A description of integrating electronic mail with the Clamav anti-virus program on the basis of configuration of the following servers: Postfix, Qmail and Exim. The micro-course contains example solutions for the mentioned mail programs.
Keywords: clamav, AV, antivirus
Basic information and structure of IPv4. Nowadays, this protocol is used as the main way of communication between the computers.
In Linux, you can find a lot of very useful and convenient-to-use tools to look inside the processes in the system. The entire life of the system is the effect of running the processes. The ability to use helpful tools, and then interpret the results obtained may decide whether the patient will survive (or the system will die).
SSH is used for remote administration of operating systems (shell and copy files). It is a secure tool that every administrator needs to know very well. Thanks to SSH, adminstrator can administer the server, and also copy files between servers, etc.
Issues addressed in this micro-course, allow the Administrator to build knowledge of how to log into the system via the remote console. Administrator willractically learn how to use Putty, Telnet or SSH programs to get to the system. Finally the Administrator wii find out how to display information about users in the network.
This course will give you practical knowledge of how to talk with the system. You will learn the commands and how to arrange them in sequences so the shell can properly interpret them. You will learn how the regular user becomes an administrator.
The way one address the data with IPv4. We disucss here, what th IPv4 address is used for, what the IPv4 address classes are, what VLSM and CIDR are, what the sepcial nad local addresses are. It is abslolutelly necessary to know these issues.
Medium of air, gives users access to the resources of the wireless network. However, due to the fact that it is an open medium it allows eavesdropping data. Micro-course shows how it is possible to secure data transmission in WLAN.
In recent years there was a huge growth of interest in protocols for voice transmission over the network. The most popular is VoIP (Voice over IP) due to its dissemination and versatility. The development of these technologies speeds up since the telecommunication operators have started to transmit calls using packet networks with different protocols to broadcast voice. In this micro-course we present the basics of VOoIP technology for building IP telephony.
Understanding the architecture of storing data on hard drive enables the administrator to prevent and detect many problems connected with the support of files and directories. This micro-course explains basic mechanisms such as VFS or EXT used by the Linux system kernel for supporting disk resources.
This micro-course will give you the practical knowledge of how to encode and decode the data and what programs and commands to use. For example, when a non-printable character in a text configuration file will not allow starting the web server it would be very important to be able to view the file content, along with information about the individual ASCII characters.
An important aspect of working as an administrator is understanding what commands are. In the Linux system there are many tools for locating a binary file which is used if a command is given in the shell. Knowing these commands will enable you to avoid errors while working with the system, which in some cases can cause serious consequences. This micro-course describes how to run commands, how to locate them with commands such as which and a way of quick search for files using the locate tool. In the Linux system extensions are not treated as the main mechanism of specifying types of files. The file content is responsible for that. To specify what the file contains, if it is an executable file and if yes then for what architecture, if it is a file with data and what type it is, you can use the discussed in this micro-course file command.
This micro-course presents the basic Linux commands intended for the administrator. The commands are: arch, uname, domainname, hostname, id, logname, uptine, finger, whoami, who. Thera are many more that will certainly, in the future, help you a lot. With the knowledge of these commands, the administrator will be able to obtain information about the state of the system, modify the host name, identify the users, get information about accounts and logins of the user.
The end of work for each script should be information about the operations of the administrator. It is done by using the most popular shell comand that is the echo command. However, in the Linux system there is also another less popular command which is printf. The differences between those commands and how to use them can be found in this micro-course. Moreover, there is a method of sending the text from the keyboard to the shell using the read command.
Micro-course widely discusses one of the basic mechanisms of the Internet - Domain Name System DNS. First, we provide information on what the structure of the Internet domain names is and where responsible registratr can be found. Then, as an example of the service's most popular server - BIND, we show its configuration, and by the way we learn the principles of operation of DNS servers. At the end of the theory we enurage you to analyze the low-level content of the DNS messages by capturing DNS traffic, and the specific examples given we shpw how to trobleshoot the operation of the DNS.
Every modern database should be compatible with the SQL language. This micro-course discusses basic operations performed from the client level and on the MySQL base using this language. The examples show the way of creating a table, adding records or updating them.
Keywords: SQL, INSERT, DELETE, SELECT
Discussion of the file system used in Linux distributions: the directory structure, the main directories and their hierarchy. Micro-course will teach how to navigate the directory structure, the importance of the concepts of relative and absolute path. You will also discover aliases of major directories in the system and the variables related to the position of the directory.