Date: Fri, 15 Dec 2000 22:04:57 -0600 From: David Kelly <dkelly@hiwaay.net> To: "Kevin Oberman" <oberman@es.net> Cc: freebsd-questions@FreeBSD.ORG Subject: Re: use of 1500 octet pings? Message-ID: <200012160404.eBG44v454729@grumpy.dyndns.org> In-Reply-To: Message from "Kevin Oberman" <oberman@es.net> of "Fri, 15 Dec 2000 11:14:16 PST." <200012151914.eBFJEGJ19767@ptavv.es.net>
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"Kevin Oberman" writes: > > Date: Wed, 13 Dec 2000 17:07:41 -0600 > > From: David Kelly <dkelly@hiwaay.net> > > Sender: owner-freebsd-questions@FreeBSD.ORG > > > > Watching reject messages on firewalls lately I've seen ICMP ECHO > > requests from web sites somebody is visiting, trying to packets of > > echo 1500 octets off us. What the heck are they trying to do? I can't > > guess an honest excuse for websites to ping visitors. And with such > > large packets. > > PMTU discovery? They may well be sending larger pings, but they don't > get to you. 1500 octets is probably the largest packet that can make > it to you without fragmentation. I don't know what they are doing but watch what happens when you try http://www.nga.gov/. Forcing MTU discovery with large pings on first access to a web site doesn't seem right. HP has sites which do the same thing. -- David Kelly N4HHE, dkelly@hiwaay.net ===================================================================== The human mind ordinarily operates at only ten percent of its capacity -- the rest is overhead for the operating system. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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