A reader of my blog discussed with the article about the BPF with me. He wanted to use the BPF for his own project and had read the FreeBSD BPF device HOWTO but several problems could not be solved.

During this e-mail discussion I found several flaws in the article and in the IMR demo program (concerning the use of the BPF_WORDALIGN macro). Hence, I updated the original article and IMR.

I hope these new versions will become even more useful than their predecessors.