Date: Sat, 01 Sep 2001 02:27:20 +0200 From: Hroi Sigurdsson <hroi@asdf.dk> To: freebsd-hackers@freebsd.org Subject: Re: Should URL's be pervasive. Message-ID: <3B902B68.E15DFA3E@asdf.dk> References: <56710000.999257324@lobster.originative.co.uk> <Pine.BSF.4.10.10108310943310.81728-100000@mail.matriplex.com> <20010831154300.B27173@dragon.nuxi.com>
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David O'Brien wrote: > Do you know how traceroute works?? For one, the destination host cannot > be listening on the port used. And you know that each progressive > traceroute packet sent out bumps the destination port by one, to help > trace the ICMP "time exceeded" / "port unreachable" responses. Only UDP traceroute requires that the port not be listened to (otherwise you wouldn't get a packet back). If using TCP you will get a packet back (RST/SYNACK/ICMP-portunreachable etc) whether the port is open or not. In theory at least.. -- Hroi Sigurdsson To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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