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Date: Sat, 13 Sep 1997 15:30:48 -0400 (EDT)
From: Brian Mitchell <brian@firehouse.net>
To: Sunthiti Patchararungruang <stt@pluto.cpe.ku.ac.th>
cc: hackers@FreeBSD.ORG
Subject: Re: Need Help about BPF
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On Sun, 14 Sep 1997, Sunthiti Patchararungruang wrote:

> Dear Sir,
> 
> 	I am a master student. My thesis is in the topic of computer
> network. I need to know that if I has a complete IP packet, already
> encapsulated with IP header, and I would like to send it to a specified
> interface, how can I do that. However, my IP packet does not have any
> information about Datalink layer address. Do I need to manage the address
> by myself.

man ip, I would probably use a raw socket

> 
> 	Someone in FreeBsd.org told me that I should use BPF. I rarely
> have the document about it, only have BPF(4) man-page and BPF data in
> ftp.ee.lbl.gov. If you also recommend BPF, please tell me where I can find
> the information about it.

if you use bpf, just write the segment. You need datalink layer too, in
the case of bpf.