Configure PF Firewall on OpenBSD 7.5

/etc/pf.conf

ext_if = "em0"
set block-policy return
set loginterface egress
set skip on lo0
block log all
pass in quick on egress proto tcp to port ssh \
    flags S/SA keep state (max-src-conn 15, max-src-conn-rate 5/3, overload  flush global)
pa...

Configure firewalld on RHEL 9

Status

systemctl status firewalld
firewall-cmd --state
firewall-cmd --list-all

Allow common services

firewall-cmd --permanent --add-service=http
firewall-cmd --permanent --add-service=https
firewall-cmd --permanent --add-service=ssh
firewall-cmd --permanent --ad...

Configure UFW on Ubuntu 24.04

Install and set defaults

apt install -y ufw
ufw default deny incoming
ufw default allow outgoing

Allow services

ufw allow ssh
ufw allow 80/tcp
ufw allow 443/tcp
ufw enable

Status

ufw status verbose

Allow from specific IP

ufw allow from 192.168.1.100 to a...

Configure Nginx as a Reverse Proxy on AlmaLinux 9

Basic reverse proxy

upstream backend {
    server 127.0.0.1:3000;
}

server {
    listen 80;
    server_name app.example.com;
    location / {
        proxy_pass         http://backend;
        proxy_http_version 1.1;
        proxy_set_header   U...

Configure Nginx as a Reverse Proxy on Arch Linux

Basic reverse proxy

upstream backend {
    server 127.0.0.1:3000;
}

server {
    listen 80;
    server_name app.example.com;
    location / {
        proxy_pass         http://backend;
        proxy_http_version 1.1;
        proxy_set_header   Up...

Configure Nginx as a Reverse Proxy on Debian 12

Basic reverse proxy

upstream backend {
    server 127.0.0.1:3000;
}

server {
    listen 80;
    server_name app.example.com;
    location / {
        proxy_pass         http://backend;
        proxy_http_version 1.1;
        proxy_set_header   Upg...

Configure Nginx as a Reverse Proxy on Gentoo Linux

Basic reverse proxy

upstream backend {
    server 127.0.0.1:3000;
}

server {
    listen 80;
    server_name app.example.com;
    location / {
        proxy_pass         http://backend;
        proxy_http_version 1.1;
        proxy_set_header...

Configure Nginx as a Reverse Proxy on NetBSD 10

Basic reverse proxy

upstream backend {
    server 127.0.0.1:3000;
}

server {
    listen 80;
    server_name app.example.com;
    location / {
        proxy_pass         http://backend;
        proxy_http_version 1.1;
        proxy_set_header   Upg...

Configure Nginx as a Reverse Proxy on OpenBSD 7.5

Basic reverse proxy

upstream backend {
    server 127.0.0.1:3000;
}

server {
    listen 80;
    server_name app.example.com;
    location / {
        proxy_pass         http://backend;
        proxy_http_version 1.1;
        proxy_set_header   U...

Configure Nginx as a Reverse Proxy on RHEL 9

Basic reverse proxy

upstream backend {
    server 127.0.0.1:3000;
}

server {
    listen 80;
    server_name app.example.com;
    location / {
        proxy_pass         http://backend;
        proxy_http_version 1.1;
        proxy_set_header   Upgrad...

Configure Nginx as a Reverse Proxy on Ubuntu 24.04

Basic reverse proxy

upstream backend {
    server 127.0.0.1:3000;
}

server {
    listen 80;
    server_name app.example.com;
    location / {
        proxy_pass         http://backend;
        proxy_http_version 1.1;
        proxy_set_header...

Configure Nginx Virtual Hosts on AlmaLinux 9

Step 1 – Create the document root

mkdir -p /var/www/example.com/html
echo '
Works!
' > /var/www/example.com/html/index.html

Step 2 – Create /etc/nginx/conf.d/example.com.conf

server {
    listen 80;
    listen [::]:80;
    server_name exam...

Configure Nginx Virtual Hosts on Arch Linux

Step 1 – Create the document root

mkdir -p /var/www/example.com/html
echo '
Works!
' > /var/www/example.com/html/index.html

Step 2 – Create /etc/nginx/sites-available/example.com

server {
    listen 80;
    listen [::]:80;
    server_name e...

Configure Nginx Virtual Hosts on Debian 12

Step 1 – Create the document root

mkdir -p /var/www/example.com/html
echo '
Works!
' > /var/www/example.com/html/index.html

Step 2 – Create /etc/nginx/sites-available/example.com

server {
    listen 80;
    listen [::]:80;
    server_name ex...

Configure Nginx Virtual Hosts on Gentoo Linux

Step 1 – Create the document root

mkdir -p /var/www/example.com/html
echo '
Works!
' > /var/www/example.com/html/index.html

Step 2 – Create /etc/nginx/conf.d/example.com.conf

server {
    listen 80;
    listen [::]:80;
    server_name exa...

Configure Nginx Virtual Hosts on NetBSD 10

Step 1 – Create the document root

mkdir -p /var/www/example.com/html
echo '
Works!
' > /var/www/example.com/html/index.html

Step 2 – Create /usr/pkg/etc/nginx/conf.d/example.com.conf

server {
    listen 80;
    listen [::]:80;
    server_nam...

Configure Nginx Virtual Hosts on OpenBSD 7.5

Step 1 – Create the document root

mkdir -p /var/www/example.com/html
echo '
Works!
' > /var/www/example.com/html/index.html

Step 2 – Create /etc/nginx/conf.d/example.com.conf

server {
    listen 80;
    listen [::]:80;
    server_name exam...

Configure Nginx Virtual Hosts on RHEL 9

Step 1 – Create the document root

mkdir -p /var/www/example.com/html
echo '
Works!
' > /var/www/example.com/html/index.html

Step 2 – Create /etc/nginx/conf.d/example.com.conf

server {
    listen 80;
    listen [::]:80;
    server_name example.c...

Configure Nginx Virtual Hosts on Ubuntu 24.04

Step 1 – Create the document root

mkdir -p /var/www/example.com/html
echo '
Works!
' > /var/www/example.com/html/index.html

Step 2 – Create /etc/nginx/sites-available/example.com

server {
    listen 80;
    listen [::]:80;
    server_name...

Configure OpenSMTPD on AlmaLinux 9

Install

# OpenBSD – built-in:
rcctl enable smtpd && rcctl start smtpd

# Other platforms:
# Ubuntu/Debian:
apt install opensmtpd
# AlmaLinux/RHEL:
dnf install opensmtpd
# Arch:
pacman -S opensmtpd

Basic /etc/mail/smtpd.conf

pki mail.example.com cert "/etc/...

Configure OpenSMTPD on Arch Linux

Install

# OpenBSD – built-in:
rcctl enable smtpd && rcctl start smtpd

# Other platforms:
# Ubuntu/Debian:
apt install opensmtpd
# AlmaLinux/RHEL:
dnf install opensmtpd
# Arch:
pacman -S opensmtpd

Basic /etc/mail/smtpd.conf

pki mail.example.com cert "/etc/s...

Configure OpenSMTPD on Debian 12

Install

# OpenBSD – built-in:
rcctl enable smtpd && rcctl start smtpd

# Other platforms:
# Ubuntu/Debian:
apt install opensmtpd
# AlmaLinux/RHEL:
dnf install opensmtpd
# Arch:
pacman -S opensmtpd

Basic /etc/mail/smtpd.conf

pki mail.example.com cert "/etc/ss...

Configure OpenSMTPD on Gentoo Linux

Install

# OpenBSD – built-in:
rcctl enable smtpd && rcctl start smtpd

# Other platforms:
# Ubuntu/Debian:
apt install opensmtpd
# AlmaLinux/RHEL:
dnf install opensmtpd
# Arch:
pacman -S opensmtpd

Basic /etc/mail/smtpd.conf

pki mail.example.com cert "/etc...

Configure OpenSMTPD on NetBSD 10

Install

# OpenBSD – built-in:
rcctl enable smtpd && rcctl start smtpd

# Other platforms:
# Ubuntu/Debian:
apt install opensmtpd
# AlmaLinux/RHEL:
dnf install opensmtpd
# Arch:
pacman -S opensmtpd

Basic /etc/mail/smtpd.conf

pki mail.example.com cert "/etc/ss...