8. Hosting a Static Website and Changing the Configuration
8.7 Changing the Port
Kadhi kadhi admin panel kiwa dusri site vegalya port var chalvavi lagte, udaharanartha 8081.
# Nginx: /etc/nginx/conf.d/admin.conf (Ubuntu: sites-available + symlink)
server {
listen 8081;
server_name _;
root /var/www/admin;
index index.html;
}
# Apache (AL2023/CentOS): add to /etc/httpd/conf.d/admin.conf
Listen 8081
<VirtualHost *:8081>
DocumentRoot /var/www/admin
<Directory /var/www/admin>
Require all granted
</Directory>
</VirtualHost>
On Ubuntu Apache, put Listen 8081 in /etc/apache2/ports.conf (not in the vhost file). Then:
- Test and reload the web server.
- Check that it listens:
sudo ss -tlnp | grep 8081. - Security group: add an inbound rule Custom TCP 8081 (from My IP for admin pages).
- CentOS Stream 9: open firewalld if active (
sudo firewall-cmd --permanent --add-port=8081/tcp && sudo firewall-cmd --reload) and allow the port in SELinux:
sudo semanage port -l | grep -w http_port_t # ports web servers may bind to
sudo semanage port -a -t http_port_t -p tcp 8081 # add 8081 if not listed
Without the SELinux step, the service fails to start with bind() to 0.0.0.0:8081 failed (13: Permission denied).
Why this matters for security
Moving a service to a non-standard port is not security – Nmap finds port 8081 in seconds. Real protection is the security group source rule (My IP only for admin ports), authentication and HTTPS. Every extra open port is extra attack surface.
Ravindra Bagale's Tip
You changed the port, the config is correct, the service is running – and still the site doesn't open. The reason: you didn't allow the new port in the security group! Many students forget this step. Check both ss -tlnp on the server and the inbound rule in AWS.
Ravindra Bagale's Tip – मराठी
Port बदलला, config बरोबर, service चालू – तरीही site उघडत नाही. कारण security group मध्ये नवीन port allow केला नाही! बरेच students ही step विसरतात. Server वर ss -tlnp आणि AWS मध्ये inbound rule – दोन्ही check करा.
Ravindra Bagale's Tip – हिंदी
Port बदला, config सही, service चालू – फिर भी site नहीं खुलती. वजह: security group में नया port allow नहीं किया! बहुत से students यह step भूल जाते हैं. Server पर ss -tlnp और AWS में inbound rule – दोनों check करो.
Lab
Serve /var/www/admin on port 8081 with Nginx. Allow 8081 only from My IP in the security group and confirm it opens from your laptop but not from your phone's mobile data.