Dummy Network Interface

[Robert Watson]

On Tue, 13 Jan 2004 ms419 at freezone.co.uk wrote:

> How does one create a dummy network interface in FreeBSD? 

Dummy in what sense?  An interface where the packets are simply dropped? 
if_tap and if_tun both provide pseudo-device in /dev that a userspace
process can attach to in order to emulate a network interface (used by
VMWare, ppp, various tunneling bits, ...)  In the absense of a process
sitting on the device, they simply drop the packets.  Although they may
get garbage-collected if unused on -CURRENT...  You can also use netgraph
to bring pseudo-interfaces, perhaps without anywhere for packets to go. 

And, I suppose, create in what sense?  Are you looking at this from a
developer perspective, or you just need one from a user perspective.  If
writing a device driver (and hence needing a starting point), if_tap and
if_tun are fairly decent models for a pseudo-interface.

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert at fledge.watson.org      Senior Research Scientist, McAfee Research