I have just installed Webmin on a Ubuntu server. According to the docs you need to open up port 10000 (which is what Webmin runs on), with this:
iptables -A INPUT -p tcp -m tcp --dport 10000 -j ACCEPT
It then says you need to apply the firewall configuration with:
However, this command doesn't work for me. Is there a different command that saves the changes on Ubuntu?