# May /dev/bpf use slow down the network stack?



## RoyalPanda (Nov 1, 2013)

Hi,

I'm quite new to FreeBSD, and *BSD in general.

I am wondering about using a FreeBSD as a firewall, and I would be able to do some 'esoteric' stuff with it. Like MAC Address translation, but not exclusively. After some research, using /dev/bpf seems to be the best option that I have.

My question is: Does using this solution slow down the network stack as what I understood, packets are sent in user space for processing?

And which approach is best: using netgraph to talk to bpf, or using my own program?

Best Regards,
Panda.


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