Date: Mon, 20 Mar 2000 15:11:04 -0500 (EST) From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu> To: Archie Cobbs <archie@whistle.com> Cc: wollman@khavrinen.lcs.mit.edu (Garrett Wollman), freebsd-current@FreeBSD.ORG Subject: Re: ICMP socket weirdness Message-ID: <200003202011.PAA88925@khavrinen.lcs.mit.edu> In-Reply-To: <200003201903.LAA05714@bubba.whistle.com> References: <200003181954.OAA77677@khavrinen.lcs.mit.edu> <200003201903.LAA05714@bubba.whistle.com>
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<<On Mon, 20 Mar 2000 11:03:07 -0800 (PST), Archie Cobbs <archie@whistle.com> said: [Quoting my original description of icmp_input()'s behavior:] >> The ICMP never passes certain packets up to raw listeners. These >> include ECHO REQUEST, TIMESTAMP REQUEST, and SUBNET MASK REQUEST >> packets -- but not the corresponding replies! So, when you ping the >> local machine, you will see the ECHO REPLY packets on all raw >> listners, but not the initial ECHO REQUESTs. When you ping from a >> remote machine, you never see the ECHO REQUEST packets because the >> kernel takes care of them, and you never see the ECHO REPLY packets >> because they are addressed to the other machine. > Is this a FreeBSD-specific thing, or to other UNIX's have this > same peculiar behavior? It was the same in 4.3. I don't have 4.2 sources handy so I can't check there -- but in any case, the answers to your questions are ``no'' and ``yes''. The raw ICMP socket is defined to only see the traffic which the kernel is unable to handle itself. -GAWollman To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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