have you also checked that beside the firewall also anti-virus is off and the network is set up to home-network (mentioned in troubleshooting-thread)? This is also important! If you have the connection direct, then try the other config with all players. Don´t know if it works with an router (but should I guess)- I use a switch. And all players and rekordbox must use the newest firmware...actual on the 2000`s is firmware 4.05 if I´m right. And I learned from the switch that it must be powered as the last to get a correct config... Maybe this helps.