Date: Thu, 25 Sep 1997 20:39:15 +1000 From: Stephen McKay <syssgm@dtir.qld.gov.au> To: Open Systems Networking <opsys@mail.webspan.net> Cc: freebsd-chat@freebsd.org, syssgm@dtir.qld.gov.au Subject: Re: debian linux ping ? *WARNING LINUX INVOLVED!!* Message-ID: <199709251039.UAA25273@ogre.dtir.qld.gov.au> In-Reply-To: <Pine.BSF.3.95.970925031328.3496A-100000@orion.webspan.net> from Open Systems Networking at "Thu, 25 Sep 1997 07:22:39 %2B0000" References: <Pine.BSF.3.95.970925031328.3496A-100000@orion.webspan.net>
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On Thursday, 25th September 1997, Open Systems Networking wrote: >While to trying to figure out why my local cable company whos offering >net access, has such flaky service, i ran across this output of ping and >cannot figure out WHY it's doing these things. Anyone have an answer? Ooh! I like puzzles. :-) >cypress: {12}ping -v idtswe1 > >76 bytes from localhost (127.0.0.1): Destination Port Unreachable >Vr HL TOS Len ID Flg off TTL Pro cks Src Dst Data > 4 5 00 4400 a758 0 0000 40 11 0024 127.0.0.1 127.0.0.1 >UDP: from port 1254, to port 512 (decimal) Looks like you were receiving mail and don't have comsat enabled in /etc/inetd.conf. And you've got a verbose ping. >First question is WHY is it showing a packet with a src and dst address as >127.0.0.1? im not pinging loopback. Because mail.local tried to talk to biff/comsat, I expect. Local to local. >64 bytes from 206.101.232.98: icmp_seq=19 ttl=252 time=61.4 ms > >Correct IP address of idtswe1 > >64 bytes from lpthomas.winning-edge.com (205.217.148.247): Echo Request > ^^^^^^^^^^^^^^^^^^^^^^^^ >NOT idtswe1.idir.net >Whoa hello where did you come from. >I think debian linux is broke :) >64 bytes from 206.101.232.98: icmp_seq=117 ttl=252 time=40.0 ms >64 bytes from 206.101.232.98: icmp_seq=118 ttl=252 time=53.3 ms >64 bytes from lpthomas.winning-edge.com (205.217.148.247): Echo Request > ^^^^^^^^^^^^^^^^^^^^^^^ >Whats the deal on that as well? It looks like linux ping isn't very picky and will display all ICMP traffic going past. It is an echo request, not a reply. Maybe the dude was doing a broadcast ping. I expected ping -v on FreeBSD to act the same, but got nothing special, even as root. I suppose there could be some kernel filtering going on, but I seem to be losing interest now. :-) You'll be wanting to "Read the Source, Luke"! Oh well, back to the grind... Stephen.
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