All depends on what IP you put on config.lua.
If you put:
127.0.01 or localhost you can enter with those IPs only in the host computer without problems.
But if you put your normal ip, or dynamic one, you will need to enter with the IP that is showed on ms-dos, the first one, but only if you're in the host computer too, normal people with the normal dynamic ip.
Or just can be a simple ports problem, you need to be sure that you have forwarded the correct ports (7171, 7172) on router and firewall.