In the current version of Parallels Workstation a RTL8029 (NE2000 compatible PCI card) network adapter is supported.
In a Linux guest OS, to be able to access an external network in the virtual machine, a ne2k-pci driver should be loaded into the Linux kernel. It is included by default, however if you are going to recompile the kernel remember to select the ne2k-pci component. In a FreeBSD guest OS you need to have the if_ed.ko module loaded.
Device Status:
Emulation:
In the Emulation group, you can select the type of network adapter to be used in your guest OS. You can choose between the Bridged Ethernet and Host-only networking.
If you select the Bridged Ethernet radio button, the Network Adapters drop-down list will show a list of all physical network adapters available on your computer. Choose one of them to connect to your virtual adapter.
The list of available adapters contains the Default adapter which always maps to Ethernet adapter that handles the default route in your system. When routing table in your system changes, default adapter mapping will change automatically. This is useful when you use a wired connection and changed it to wireless one. With Default adapter selected you don't need to stop the virtual machine and select the currently active adapter.
Advanced
You can find native Realtek RTL8029 drivers for many different guest OSes in the Parallels Tools pack shipped together with the Parallels Workstation.
In Windows 2000/XP/2003 guest operating systems you can improve network performance by installing a specially developed PRLETH driver that can be found in the Parallels Tools pack.