OCI: Port 80 and 443 Became Inaccessible After Reboot

APPLIES TO

Oracle Cloud Infrastructure - Version N/A and later

Linux x86-64

 

SYMPTOMS

3rd party Web Application Site became inaccessible after server reboot even the port 80 and 443 is up and running

netstat – tulpn | egrep "80|443" 
tcp        0      0 0.0.0.0:443             0.0.0.0:*               LISTEN      0          37712      2831/nginx: master   off (0.00/0/0) 
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      0          37711      2831/nginx: master   off (0.00/0/0) 

CAUSE

Firewalld service started upon reboot.

         Starting firewalld - dynamic firewall daemon... 
[  OK  ] Started firewalld - dynamic firewall daemon. 

Checked the status of of firewalld service

firewalld.service - firewalld - dynamic firewall daemon 
  Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled) 
  Active: active (running) since Tue 2023-11-21 21:41:10 -03; 6min ago 
    Docs: man:firewalld(1) 
Main PID: 1365 (firewalld) 
   Tasks: 2 (limit: 48663) 
  Memory: 31.6M 
  CGroup: /system.slice/firewalld.service 
          └─1365 /usr/libexec/platform-python -s /usr/sbin/firewalld --nofork --nopid 
Nov 21 21:41:09 hostname systemd[1]: Starting firewalld - dynamic firewall daemon... 
Nov 21 21:41:10 hostname systemd[1]: Started firewalld - dynamic firewall daemon.