I need to open a port in linux 8, I set the firewall to medium. That doesn't work so I try and do the custom selection. I try to open the port that way and linux 8 keeps reverting back to the original it was set to, to begin with. I need to open port 2001. I have set it up in iptables and I have set it up in services. I don't know what else to do. So if anyone can be of some help i would greatly appreciate it.

try this, change the 127.0.0.1 to your IP and it will allow tcp connections in on port 2001, if you need UDP just type in udp instead of tcp. iptables -A INPUT -p tcp -d 127.0.0.1 --dport 2001 -j ACCEPT

Does it work with the firewall disabled ("service iptables stop")? If yes, you know it's the firewall that's holding you back. What are you using to modify the firewall's rules? lokkit (also setup, then Firewall configuration)? redhat-config-securitylevel? Either way should work. Either way, I'd probably restart iptables after modifying the settings ("service iptables restart"). Plus, are you sure you are putting the right protocol (tcp, udp, etc.) after the port number in "Other ports"? I also don't see 2001 as a port in the default /etc/services file. Are you adding this correctly? Good luck.