Check if port is open or blocked in iptables April 20, 2015 The Geek Decoder Leave a comment Administration, Iptables # iptables -L -n # iptables -L -n | grep :PORT Post navigation ← Stop firewalld on CentOS 7Warning: Unknown: open(/tmp/sess, O_RDWR) failed: Permission denied (13) in Unknown on line 0 →