Help creating bpf0 device (bpf won't do it for me)

Chris Rees utisoft at
Sat May 9 14:46:14 UTC 2009

2009/5/8 D C <invocatum at>:
> Hello,
> I'm in the final stages of setting up a new wireless connection but have
> been having problems getting bpf running.  For some reason, even though bpf
> has been compiled into a new kernel, the system won't automatically create a
> bpf0 device.  On boot, the system complains "pcap_open_live: (no devices
> found) /dev/bpf0: No such file or directory".
> The ultimate goal is to have this laptop connect wirelessly to my
> WPA2-protected WAP (already working fine with other boxes) using a static
> IP.
> I've successfully compiled in support for the Atheros-based PCMCIA card,
> edited rc.conf to exclude DHCP and to use wpa_supplicant.conf, and
> eventually compiled in bpf when I started receiving the pcap_open_live
> messages.
> I suspect bpf is needed not for DHCP which is not running, but for some of
> the parameters I added to wpa_supplicant.conf, which is as follows:
> ctrl_interface=/var/run/wpa_supplicant
> ctrl_interface_group=wheel
> network={
> ssid="my_ssid"
> scan_ssid=1
> proto=RSN
> key_mgmt=WPA-PSK
> pairwise=CCMP
> psk="my_ssid"
> }
> If someone would be so kind as to explain what is calling bpf and how I can
> create a bpf0 device by hand, I would be indebted.
> Thanks...

[chris at amnesiac]~% ls /dev/bpf0
[chris at amnesiac]~% grep bpf /root/AMN
[chris at amnesiac]~% grep bpf /root/AMNESIAC.conf
# The `bpf' device enables the Berkeley Packet Filter.
# Note that 'bpf' is required for DHCP.
device          bpf             # Berkeley packet filter
[chris at amnesiac]~%

Are you *sure* you've compiled in bpf? Did you reboot after recompiling?


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