📥 Debian Optimizer

Bash script automatically configures and optimizes the Debian(Ubuntu) server.

Before running the script, create a key pair and place the public key in the file /.ssh/authorized_keys .

ssh-keygen -t rsa
cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
cat ~/.ssh/id_rsa

copy private key

SSH password authorization will be disabled and the port will change to 2222, if you have chosen SSH, NFT optimization or Everything

Ensure that the sudo and wget packages are installed on your system:

apt install -y sudo wget

🟢 Run

💠 Root Access is Required. If the user is not root, first run:

sudo -i

💠 Then:

wget "https://raw.githubusercontent.com/Onair-santa/Debian-Optimizer/main/optimizer.sh" -O optimizer.sh && chmod +x optimizer.sh && bash optimizer.sh

It performs the following tasks:

💠 Fix hosts file and DNS (temporarily) :

• Check and append 127.0.1.1 and server hostname to /etc/hosts. Original hosts file is backed up at /etc/hosts.bak.
• Append 8.8.8.8 and 8.8.4.4 to /etc/resolv.conf. Original dns file is backed up at /etc/resolv.conf.bak.

💠 Update and Clean the server:

• Update
• AutoRemove
• AutoClean

💠 Install Useful Packages:

curl htop jq nftables wget speedtest-cli

💠 Install Synth-Shell :

• More detailes https://github.com/andresgongora/synth-shell

💠 Set the server TimeZone to VPS IP address location.

💠 Create & Enable SWAP File:

• Swap Path: "/swapfile"
• Swap Size: 1Gb

💠 Disable IPv6 Support.

💠 Optimize the SYSCTL Configs.

• Optimize SWAP.

• Optimize Network Settings.

• Activate BBR.

• Optimize the Kernel.

  Original file is backed up at /etc/sysctl.conf.bak.

💠 Optimize SSH:

• Port 2222 (change 22 → 2222)
• Remove PasswordAuthentication
• Enable PubkeyAuthentication
• Back up the original sshd_config file.
• Disable DNS lookups for connecting clients.
• Remove less efficient encryption ciphers.
• Enable and Configure TCP keep-alive messages.
• Allow agent & TCP forwarding.
• Enable gateway ports, Tunneling and compression.
• Enable X11 Forwarding. Original file is backed up at /etc/ssh/sshd_config.bak.

💠 Optimize the System Limits:

• Soft and Hard ulimit -c -d -f -i -l -n -q -s -u -v -x optimizations.

💠 Install & Optimize NFTables

• Open port 2222 for SSH
• Open ports TCP 80 443

💠 Install Crowdsec security (optional, analog fail2ban)

• More Details: https://github.com/crowdsecurity/crowdsec
• Linux, SSH, Firewall bouncers

💠 Install Fail2ban security

• More Details: https://github.com/fail2ban/fail2ban

• Jail enabled: sshd(port=2222), recidive(allport (settings in file jail.local)

• Status command:

  fail2ban-client status
  fail2ban-client status sshd
  fail2ban-client status recidive
  

Disclaimer

This script is provided as-is, without any warranty or guarantee. Use it at your own risk.

💠 Thanks

• hawshemi
• andresgongora
• Fail2ban
• Crowdsec