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 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.
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.
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.
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.
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."
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.
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.
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.
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.
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.
Basic information and structure of IPv4. Nowadays, this protocol is used as the main way of communication between the computers.
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.
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.
This micro-course describes the mechanism of exchanging a name for the IP address used in Linux systems. Both the local base, i.e. the /etc/hosts file and the distributed DNS mechanism were described.
Keywords: DNS, hosts, in-addr.arpa, delegation, zone, DNS, record RR
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.
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.
What is the reason people see a picture of admin sitting and doing nothing? Thanks to protocols such as DHCP administrator does not need to run around and manually configure the computers on the network. On one hand the facilitation and on the other the correct IP address scheme. DHCP configuration requires adequate knowledge, we take a look at DHCP in this micro-course.
This micro-course discusses the rules necessary for the proper design of a computer network. You'll learn why you should not connect network devices in the "chain". Instead, you should use a multi-layered concept. The course belongs to the network designers preparation courses.
Micro-course concentrates on operation of FTP - the protocol used to transfer files over the Internet. - It is the oldest protocol, which main task is two-way file transfer. Nowadays more and more popular are HTTP protocols - small files are downloaded directly from a web page or the BitTorrent protocol is used for the propagation of large files. However, for example, when creating a file repository for third party company (eg leaflets, high-resolution product images) the FTP is still unreplaceable. The course describes how to test the FTP server on the basis of information about the operation of this protocol. The course also explains why some older firewalls cannot handle this protocol and how to fix it.
The micro-course presents advanced network firewall mechanisms managed by the iptables command. The information contained enables creating a firewall beginning with basic procedures, using standard rules of blocking and finishing with stateful procedures and logging information.
Keywords: iptables, rcSuSEfirewall2, conntrack
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
Micro-course presents the Frame Relay technology, which solved the problem of lck of high speed transmission and bandwidth in WAN networks. In addition, it proved to be more cost-effective comparing to the previous solutions, which contributed to its rapid growth and the displacement of the older X.25 technology.
In this micro-course there is a description of the Linux system kernel. It talks about its main features, i.e. mechanisms such as multitasking, reentrant, code sharing, or preemption. Without this information it is hard to understand what the kernel does to support processes.
Everyone, when crowling the Internet, develops his own methods of search interesting resources. Public Web search engines give invaluable service. Of course the quality of the results obtained is directly proportional to the knowledge of the user about their use. Therefore, you should be thoroughly familiar with the principles of creating advanced queries, at least for a few major search engines. This allows more efficient (faster) serach process. If you want to find out what ErrorMessage means all you have to do is just to copy it and paste it into a search engine. Of course, this „message” should be included in quotation marks. If someone has had a similar problem, the Internet will most likely keep his message and a description of the problem. If thre is the answer to his post (posted on one of the public newsgroups) you can also read it. In this part of the course we will present the resources on the Internet, from where you should start searchig, and you should know. Of course, there will be just few od them, other interesting network addresses can be found in the course content. We also present here the methods for converting numbers from decimal system to binary and hexadecimal systems. It is a very valuable skill needed later by administrators in a situation of dealing with MAC, IPv4 and IPv6 addresses. We strongly encourage you to exercise! How to measure „speed” of network? Find the answer here.
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