To people who've been having trouble with setting up a LAN connection and are only planning to play with a small group, you can try Hamachi instead. Granted it's not truly an offline method (or LAN for that matter), it's more of a last resort kind of thing. I've tried most of the guides here on the thread and none of them seem to work and the problem might be with my own network settings itself (like having a static or dynamic IP etc.)
First ensure that the ff ports are open: 6900, 5121, 6121 (You can find out how to do it here: -- REMOVED --
Refer to this guide: http://forum.ragezone.com/f84/guide-setting-server-hamachi-router-169296/
Follow everything to the letter except the portion about GRF files, and as for the sclientinfo just go to 07_Clean_kRO_Client/data and use notepad or whatever on the XML (Note you only have to do that last bit on other PC's, the HOST PC can remain untouched)
Once finished, just follow standard procedure, that is, OpenServer (Greenflag) > Runserver.bat > patched.exe