I've noticed that with 9.0-RC1, usbus[0-9] are seen as network interfaces. I 
figured this is need for usbdump to work.
(This isuue has been raised before [1], but no helpful replies were given).

I find this behavior rather annoying:

usbus0 is the default interface (in 8.2, my primary network interface was 
# tcpdump 
tcpdump: WARNING: usbus0: That device doesn't support promiscuous mode
(BIOCPROMISC: Operation not supported)
tcpdump: WARNING: usbus0: no IPv4 address assigned
tcpdump: packet printing is not supported for link type USB: use -w

Various tools (netstat, tcpdump, wireshark, my network monotoring dockapp) now 
list 8 additional interfaces:
# netstat -i
Name    Mtu Network       Address              Ipkts Ierrs Idrop    Opkts 
Oerrs  Coll
usbus     0 <Link#1>                               0     0     0        0     
0     0
usbus     0 <Link#2>                               0     0     0        0     
0     0

I can do rather silly things, that at best will do nothing:
# ifconfig usbus0
# usbdump -i lo0

Some applications seem to check the link type, so that unsupported interfaces 
are not shown. But the behavior isn't even consistent in the base system:
- ifconfig -a doesn't show usbus interfaces, but lets you happily configure 
- tcpdump -D shows the interfaces, but bails out if you actually start
- netstat shows them
- systat -ifstat only lists real interfaces

Do all these applications need to be patched, or can this be fixed in a single 
place (in the kernel)?

Is there a kernel option/sysctl/etc. to disable this behavior? I'm most likely 
not going to need usbdump in the foreseeable future.

[1] http://lists.freebsd.org/pipermail/freebsd-stable/2011-

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