Date: Mon, 7 Jan 2002 23:43:05 -0800 From: Rachel Leising <rleising@sbcglobal.net> To: cjclark@alum.mit.edu Cc: freebsd-net@FreeBSD.ORG, rleising@sbcglobal.net Subject: Re: name resolution problems and "full socket buffers" Message-ID: <a05100300b860474d160e@[10.0.1.26]> In-Reply-To: <20020106223931.E2029@gohan.cjclark.org> References: <a05100300b85ea4d919a2@[10.0.1.26]> <20020106223931.E2029@gohan.cjclark.org>
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Crist, Please see output in-line below... >On Sun, Jan 06, 2002 at 05:22:00PM -0800, Rachel Leising wrote: >> >> -- >> I can't seem to get name resolution working correctly. >> >> According to sniffer output, the dns query goes out fine and the >> response comes back just fine. However, my machine then replies to >> the dns server with an ICMP "port unreachable message"... regardless >> of the ephemeral port used by my machine as the source port for the >> dns query. > >Could you post the actual tcpdump(1) output, > > # tcpdump -vvvn 'udp && port 53' > >Just in case you are missing something. # tcpdump -vvn 'udp && port 53' tcpdump: listening on wi0 23:03:06.652249 10.0.1.14.1068 > 10.1.1.53: [ udp sum ok ] 26929+ A? www.yahoo.com. [ |domain ] (ttl 64, id 120, len 59) 23:03:06.674992 63.203.35.55.53 > 10.0.1.14.1068: 26929 q: A? www.yahoo.com. 7/8/8 www.yahoo.com. CNAME[ |domain ] (DF) (ttl 249, id 16300, len 453) 23:03:11.660476 10.0.1.14.1068 > 10.1.1.53: [ udp sum ok ] 26929+ A? www.yahoo.com. [ |domain ] (ttl 64, id 122, len 59) 23:03:11.686633 63.203.35.55.53 > 10.0.1.14.1068: 26929 q: A? www.yahoo.com. 7/8/8 www.yahoo.com. CNAME[ |domain ] (DF) (ttl 249, id 16301, len 453) 23:03:16.670665 10.0.1.14.1069 > 10.1.1.53: [ udp sum ok ] 26930+ MX? www.yahoo.com. [ |domain ] (ttl 64, id 124, len 59) 23:03:16.800894 63.203.35.55.53 > 10.0.1.14.1069: 26930 q: MX? www.yahoo.com. 1/1/0 www.yahoo.com. CNAME[ |domain ] (DF) (ttl 249, id 16302, len 153) 23:03:21.680620 10.0.1.14.1069 > 10.1.1.53: [ udp sum ok ] 26930+ MX? www.yahoo.com. [ |domain ] (ttl 64, id 126, len 59) 23:03:21.703735 63.203.35.55.53 > 10.0.1.14.1069: 26930 q: MX? www.yahoo.com. 1/1/0 www.yahoo.com. CNAME[ |domain ] (DF) (ttl 249, id 16303, len 153) > >> nestat -s also shows the following udp counters incrementing: >> >> "x dropped due to no socket" > >This is what I would expect for what you describe... > >> "y dropped due to full socket buffers" > >Hmmmm... > >Could we double-check the firewall issue, > > $ sysctl net.inet.ip.fw.enable net.inet.ipf.fr_running # sysctl net.inet.ip.fw.enable sysctl: unknown oid 'net.inet.ip.fw.enable' # sysctl net.inet.ipf.fr_running sysctl: unknown oid 'net.inet.ipf.fr_running' > >And see the full output of, > > $ netstat -s -p udp # netstat -s -p udp udp: 82 datagrams received 0 with incomplete header 0 with bad data length field 0 with bad checksum 0 with no checksum 15 dropped due to no socket 0 broadcast/multicast datagrams dropped due to no socket 67 dropped due to full socket buffers 0 not for hashed pcb 0 delivered 19 datagrams output > $ netstat -an -p udp # netstat -an -p udp Active Internet connections (including servers) Proto Recv-Q Send-Q Local Address Foreign Address (state) udp4 0 0 *.68 *.* udp4 0 0 *.* *.* udp4 0 0 *.514 *.* udp6 0 0 *.514 *.* > $ host testhost # your DNS test here # host www.yahoo.com #the tcpdump command above was initiated immediately before this > $ netstat -s -p udp # netstat -s -p udp udp: 289 datagrams received 0 with incomplete header 0 with bad data length field 0 with bad checksum 0 with no checksum 48 dropped due to no socket 0 broadcast/multicast datagrams dropped due to no socket 241 dropped due to full socket buffers 0 not for hashed pcb 0 delivered 52 datagrams output > $ netstat -an -p udp # netstat -an -p udp Active Internet connections (including servers) Proto Recv-Q Send-Q Local Address Foreign Address (state) udp4 0 0 10.0.1.14.1068 10.0.1.1.53 udp4 0 0 10.0.1.14.1069 10.0.1.1.53 udp4 0 0 *.68 *.* udp4 0 0 *.* *.* udp4 0 0 *.514 *.* udp6 0 0 *.514 *.* thanks again, Rach >-- >"It's always funny until someone gets hurt. Then it's hilarious." > >Crist J. Clark | cjclark@alum.mit.edu > | cjclark@jhu.edu >http://people.freebsd.org/~cjc/ | cjc@freebsd.org -- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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