Npcap is the preferred network backend and is used by default when a compatible installation is available. Follow Npcap Installation, then select the physical Ethernet adapter directly on the emulated NIC. Avanti falls back to its bundled Migration Specialties MsiPcap driver when supported Npcap cannot be loaded. Npcap is not supplied or licensed by Migration Specialties; review its license for the intended use. If an installed Npcap copy is not licensed for Avanti use, add use_npcap_driver = false to the top-level control component with a text editor before first opening the file in the Configuration Utility or emulator. For a configuration already opened under Npcap, set the same property in VLC [+], save, close the Configuration Utility, and reopen it before further use. This prevents subsequent Npcap loading and refreshes the Interface lists for MsiPcap. Npcap normally supports host-to-guest and same-host guest-to-guest traffic without a TAP adapter or Windows Network Bridge.

Avanti also supplies its own legacy NDIS5 backend, MsiPcap. MsiPcap remains available as a supported fallback and is installed by default, but it suppresses locally transmitted packet reflection. A guest can therefore communicate with systems beyond the Windows host while communication with that host or another Avanti instance on the same host is unavailable. This does not indicate failure of the external network path.

First try MsiPcap with the selected physical adapter directly. If host-to-guest or same-host guest-to-guest communication is required and does not work, use the MsiPcap TAP Bridging procedure. One local emulator needs one TAP adapter. Multiple local emulators need one separate TAP adapter per emulator, with all of those TAP adapters placed in the same Windows Network Bridge; do not attach every emulator to one shared TAP adapter. Add one physical adapter to that bridge only when the bridged guests also need the external network.

A wired Ethernet adapter is strongly preferred. Wireless adapters and virtual switches can impose additional MAC-address or promiscuous-mode restrictions; see Networking with Wireless Ethernet and Promiscuous Mode.