Linux bash shell-scripting best practise and basic commands

Linux bash shell-scripting best practise and basic commands Sharing some notes from my studies! http://www.davidpashley.com/articles/writing-robust-shell-scripts/ http://www.tecmint.com/basic-shell-programming-part-ii/ Ubuntu - https://help.ubuntu.com/community/Repositories/CommandLine dns duck duck - https://www.duckdns.org/why.jsp https://blog.malwarebytes.com/threat-analysis/2017/01/new-mac-backdoor-using-antiquated-code/ http://unix.stackexchange.com/questions/227070/why-does-a-z-match-lowercase-letters-in-bash https://www.linuxtrainingacademy.com/linux-commands-cheat-sheet/ 1 – SYSTEM INFORMATION # Display Linux system information uname -a # Display kernel release information uname -r # Show which version of redhat installed cat /etc/redhat-release # Show how… Continue reading Linux bash shell-scripting best practise and basic commands

Cisco ASA Firewall troubleshooting show conn and the meaning of flags

Reminder of Cisco ASA Firewall troubleshooting "show conn" and the meaning of "flags", hands on work! If you are looking at the connections on the firewall, understanding the connection's flags is important to understand the status of the connections, specially if you are troubleshooting or want to confirm a connection. Cisco ASA firewall command "show… Continue reading Cisco ASA Firewall troubleshooting show conn and the meaning of flags

openssl how to protect your .pem key file with a passphrase

Situation/Task: When creating a virtual machine on AWS EC2, you can create and download a new SSH key for this instance.  These keys do not come with passphrase protection.  This means if someone "finds" your key they can use it without restriction. Action: Good news, we can add a layer of protection by adding a passphrase password… Continue reading openssl how to protect your .pem key file with a passphrase