For a dig with dns request flow response use

dig hostname.tld +trace

First part of ipsec site2site VPN

This setup is done on Mikrotik (or any similar router side)

Allocation setting example, work both for cluster setting or index settings

check status
ipsec status

check connections
ipsec statusall

check certs
ipsec listcerts

Set at the beginning of bash script:

set -Eeuxo pipefail

set -e
The -e option will cause a bash script to exit immediately when a command fails.

nmap - checking open ports and footprinting
MSF - Metasploit framework
DIRB - enumerate files on webserver
Wireshark - network analytics
Wfuzz - bruteforcing web applications
sqlmap - detection and exploitation of SQL injection flaws

10 pillars of IT security:
1. Sanitize Inputs
2. Audit services
3. Backups onsite && ofsite , test backups
4. Principle of least privileges (no one logs as root, ever)
5. Zero trust networks, 2FA
6. Key-based authetification

In case you accidentally commit file you did not want, e.g. .swp from vim use:

git rm unwanted_file.swp

Check if file does not appear anymore
git commit --amend

Export and Import packages list

Export
dpkg --get-selections

Import
dpkt --set-selections