Scapy sniff() doesn't turn in loop

[gharbit]

Hi community,

HW config: Board: RPI4 USB wifi: Alfa awus036acs (RTL8811AU chipset)

SW config: OS Buster 10 Kernel Linux 5.10.103 Scapy Master branch

I'm implementing on an RPI4 a beacon packet sniffer based on the scapy-python package. sniffer.txt I change the wireless frequency channel every 100ms. I decode the frame and I extract the different fields. For debug purpose, I display every time the OUI field.

At startup, the sniffer works continuously for 1 minute. All detected OUI are displayed. After that, the sniffer stops (no OUI displayed) for many seconds (30 - 50 sec) and then it restarts working for around 10 sec. Then stops again. and so on.

Why the sniffer stops frequently? Isn't possible to sniff infinitely?

Thanks for your support.

[gharbit]

Any update?

[p-l-]

Hi,

Can you sniff using tcpdump while your script is running? Do you see the same periods with no packet displayed?

Also, could you provide the exact (not redacted) script so that it can be tested?

[stryngs]

@gharbit I have seen this behavior in the past. It is not scapy, but the NIC itself. It will drop out of monitor mode. I would love a snip of code that showcases this as it is a very random bug and if you can replicate it, that would solve a good bit of issues =).

Can we see the full code please? As well do this with your NIC inserted:

airmon-ng

Please share the output.

[p-l-]

Closing for inactivity