Do Start/Orb -> Run, NCPA.CPL [Enter]
Select the Local Area Connection (the ethernet adapter), then right-click on it and choose Properties.
Click the Advanced button on the Properties dialog.
If 192.168.27.1 is in the Default Gateways section, select it and click Remove.
If 192.168.27.1 is NOT in the Default Gateways section, then it is being set as an alternate gateway by your DHCP server and the problem needs to be addressed there, not in the client machine[s].