Running a FreeBSD 6.x guest on an ESX server may cause the following lines on the console:

This renders the system pretty unusable. The shape of the lnc driver is not that good (hence it has been deprecated from FreeBSD 7 and replaced by the le driver). Fortunately, VMWare ESX offers another network interface which works better in combination with FreeBSD. To switch network interface, follow these steps:

1. Open the VMWare Infrastructure Client.
2. Shut down the FreeBSD guest.
3. Open the datastore on which the FreeBSD guest resides.
4. Download the *.vmx file to your computer
5. Add the following line into this file:
   
   ethernet0.virtualDev="e1000"
6. Upload the *.vmx file back to the same folder in the datastore.
7. Eventually replace occurences of lnc0 to em0 in your configuration files.