Configure OpenDKIM with Postfix on Debian What are opendkim signing criteria? And how Configure OpenDKIM with Postfix on Debian? Our goal is configure OpenDKIM to sign emails for multiple domains. Linux Debian Security Networking
Linux TCP keepalive TCP keepalive settings play a crucial role in network performance and resource management. By following the best practices and adjusting the settings to suit your specific needs, you can optimize your system’s ability to detect and clean up stale network connections while maintaining optimal performance. Networking Linux
How To Find Out Hard Disk Specs / Details on Linux Linux comes with various commands to find out information about your hard drive. I recommend hdparm command, which provides a command-line interface to various hard disk ioctls supported by the stock Linux ATA/IDE device driver subsystem. This command reads/request identification information such as disk size, description, and much more directly from the drive, which is displayed in a new expanded format. Let us see various Linux disk info commands to print hard disk drive details on screen. Linux Linux Utilities
rsyslog on debian server Enable Rsyslog Logging on Debian This step by step tutorial will take you through how to enable rsyslog logging on Debian 12. Debian 12 bookworm uses systemd-journald logging by default. As such, it has deprecated the use of Rsyslog for logging so as to prevent the log messages being written twice on disk. So, how can you enable rsyslog logging on Debian 12 and higher? Rsyslog vs Journald Rsyslog and Systemd-journald are both logging systems commonly used in Linux distributions for collecting and storing log data. Debian
Illustrated introduction to Linux iptables Gee, it's my turn to throw some light on iptables! There are hundreds or even thousands of articles on the topic out there, including introductory ones. I'm not going to put either formal definitions here nor long lists of useful commands. I would rather try to use layman's terms and scribbling as much as possible to give you some insights about the domain before going to all these tables, rules, targets, and policies. Networking
BIND: Disabling IPv6 responses in bind dns server When using Bind9 as DNS service in your own network, it can be helpful to disable IPv6 (AAAA) responses to avoid the client to try to communicate via IPv6 if it hasn't been setup. Debian Linux Networking
BIND DNS server - permission denied How Fix BIND DNS server permission denied problem after log directory or log file change. Bind server failed with error: isc_stdio_open failed: permission denied Debian Linux Networking
Bonding - teaming 802.3ad LACP on Debian Server NIC teaming (Ling Aggregation) presents an interesting solution to redundancy and high availability in the server/workstation computing realms. With the ability to have multiple network interface cards, an administrator can become creative in how a particular server accessed or create a larger pipe for traffic to flow through to the particular server. Debian Linux Networking
Debian - Source Routing In some circumstances we want to route packets differently depending not only on ip destination addresses, but also on other packet fields: source address, IP protocol, transport protocol ports, or even packet payload. This task is called policy based routing - PBR. Debian Linux Networking
Debian Permanent Static Routes In this tutorial we are going to learn how to add permanent (persistent) static route in Debian or Ubuntu Linux. Debian Linux Networking
Webserver in bash - execute bash command Do you want a quick, dirty, and unsafe way to execute commands to your Linux box over HTTP? You can use the following hack! I don't recommend using this for a production system or something more important than a hobby project. Linux Bash
Bash Parameter Substitution Table 1: Bash Parameter Substitution Variable Description ${parameter:-defaultValue} Get default shell variables value ${parameter:=defaultValue} Set default shell variables value ${parameter:?"Error Message"} Display an error message if parameter is not set ${#var} Find the length of the string ${var%pattern} Remove from shortest rear (end) pattern ${var%%pattern} Remove from longest rear (end) pattern ${var:num1:num2} Substring ${var#pattern} Remove from shortest front pattern ${var##pattern} Remove from longest front pattern ${var/pattern/string} Find and replace (only replace first occurrence) ${var//pattern/string} Find and replace all occurrences ${! Linux Bash Development
