>Synopsis: Add example to ifconfig(8) for wireless monitor mode
>Category: documentation
>Environment:
System : OpenBSD 5.6
Details : OpenBSD 5.6 (GENERIC) #310: Fri Aug 8 00:14:24 MDT 2014
[email protected]:/usr/src/sys/arch/amd64/compile/GENERIC
Architecture: OpenBSD.amd64
Machine : amd64
>Description:
It would be helpful to add an example of how to put a wireless card
into monitor (rfmon) mode. The man pages for various wireless cards
(such as athn(4), urtwn(4)) mention monitor mode but not how to set
it.
I scoured ifconfig(8) and device man pages for days without finding
a hint. Finally I resorted to writing a C program with libpcap to
turn on monitor mode. Only then did I notice in ifconfig output
that monitor mode is related to mediaopt.
There is a hint in ifconfig(8) already to look at output from:
# ifconfig interface media
but it was too oblique for me to appreciate the connection.
>Fix:
Here is a patch.
--- src/sbin/ifconfig/ifconfig.8.orig Fri Jan 30 04:00:54 2015
+++ src/sbin/ifconfig/ifconfig.8 Fri Jan 30 04:47:19 2015
@@ -1568,6 +1568,12 @@
Scan for wireless networks using bwi0:
.Pp
.Dl # ifconfig bwi0 scan
+.Pp
+Put the athn0 wireless interface into monitor (rfmon) mode.
+Refer to the interface's driver-specific man page to see if
+the card supports monitor mode:
+.Pp
+.Dl # ifconfig athn0 mediaopt monitor
.Sh DIAGNOSTICS
Messages indicating the specified interface does not exist, the
requested address is unknown, or the user is not privileged and
