Security: Tips to Keep Your Ubuntu Linux Server Secure

This updated guide examines Security: Tips to Keep Your Ubuntu Linux Server Secure and organizes the essential facts, background, and practical takeaways in clear American English.

as 2097152 ___________________ data 131072 ___________________ memlock 131072 ___________________ rss 1013352 ___________________ hard nproc 128

These limits stipulate that users can use 128 processes, with the maximum address space of 2GB, the smallest data size and the locked address in memory of 128MB, saving file size limits. Maximum stay is 1GB. System log files As a system administrator, log log files are one of your best friends. If you follow these files regularly, carefully, you will detect errors in the system as soon as they appear. So you can solve almost any problem before they arise. Unfortunately, the ability to care about these log files is decreasing. So administrators often only use software to perform log processes, alert them to certain events, or write their own options in a number of languages such as Perl and Python. Log records are usually located in the directory ' / var / log '. After your server has been running for a while, you will see a lot of old log file versions are increasing in this directory. Many of them are compressed in the gzip compression program (with the extension ' .gz '). Here are some log files to note:

• / var / log / syslog - normal system log file
• /var/log/auth.log - log files that authenticate the system
• /var/log/mail.log - system log file system
• / var / log / messages - normal log messages
• / var / log / dmesg - kernel message cache message, usually from system startup.

Toolbox Log toolbox When reviewing log files, there are a few selection tools that you have to use. The last part of the printed utility is by default the last ten lines of the file, which is a small option that gives information about the last time you access the log file. $ tail / var / log / syslog With the -f parameter, the tail is included in the form below, it will open the file and show the change on the screen to let you know. The z.grep , zcat , zless files also act like the corresponding files without the 'z' at the beginning. These files are gzip compressed files. For example, to retrieve a list of lines in all compressed log files with the word ' warthog ', simply provide the following command: $ zgrep -i warthog /var/log/*.gz Your Toolbox toolbox handles empirical development logs and based on your references, but you should search in apt-cache log files first. A bit of network security Network security management is another component, provided by the operating system in a fairly wide array. There is not much difference between Ubuntun and other Linux distribution models. The iptables command is the front end to the very powerful Linux firewall tables. Unfortunately, manipulating with iptables can be much more difficult when you're trying to set up integrated firewall policies. The command below deletes all packets coming from a bad domain: $ sudo iptables -A INPUT -s www.slashdot.org -j DROP The documentation, implementation methods and articles about iptables are available on the Internet in large numbers and the main page system provides detailed information on the appropriate options. You should take some time to learn about iptables because it will allow you to install security mode on any Linux mechanism and it will be easier to learn about other OS firewall systems. The final point of attention on security In this article we have just skimmed the surface problems of system security. Although we have tried to give you good suggestions on where to start and where you can learn more. But really, there is no perfect security system. Security does not mean completely eliminating the violations, but just making them difficult to exploit, difficult to attack. This definition can be changed easily. Because it depends on the attacker. If the attacker is a young child, living in the basement, chewing on a cold pizza, it can be frustrating, easily giving up if your security barrier is too safe. But if you are keeping expensive confidential information, no matter how secure the security system is, it can be broken someday. Because destructive activity now comes from the point of view of the attacker's price and profit. Security is also quite obvious, as it is developed as a concept in computer science. Good security requires a deep understanding of the activities within the computer system. However, there will be no significant improvements if you have a deep understanding of it without knowing where to start. You can start today, follow the above references, and use it to improve your future security knowledge.