Date: Wed, 24 Mar 2004 22:59:11 +0100 From: Lutz Petersen <akio@despammed.com> To: freebsd-net@freebsd.org Subject: Re: BIND: Lookup of CNAME records Message-ID: <406204AF.5050600@despammed.com> In-Reply-To: <20040319193514.GB54073@blossom.cjclark.org> References: <6686.1079661277@www27.gmx.net> <20040319193514.GB54073@blossom.cjclark.org>
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Crist J. Clark wrote: > How long does it take to do a reverse-lookup on the result of the > previous lookups? The applications may be trying to resolve a PTR > record for the final IP address they end up with. Reverse lookups work fine. But I do not think PTR lookups are an issue in this case (see below). > You can try the following two tests and compare the difference, > > 1) Put the two external servers in resolv.conf, and run, > > # tcpdump -s512 port 53 > > And try your ftp or telnet. > > 2) Put 127.0.0.1 back into resolv.conf, clear the cache of the local > BIND (not sure of a way to do that other than killing and > restarting in 8.x.x), and run the same thing, > > # tcpdump -s512 port 53 > > And again try the ftp or telnet. I am enclosing the results of these two tests. For better readability I have removed the time offset and replaced my IP number with "me", the forwarder's IP with "fw". (1) 00:00.000000 me.49235 > fw.domain: 1081+ AAAA? ftp.de.freebsd.org. (36) 00:00.235195 fw.domain > me.49235: 1081 2/0/0 CNAME ftp4.de.freebsd.org., CNAME ftp.leo.org. (77) (DF) 00:00.235648 me.49236 > fw.domain: 1082+ A? ftp.de.freebsd.org. (36) 00:00.850987 fw.domain > me.49236: 1082 3/0/0 CNAME ftp4.de.freebsd.org., CNAME ftp.leo.org., A 131.159.72.23 (93) (DF) (2) 00:00.000000 me.domain > fw.domain: 8207+ [1au] AAAA? ftp.de.freebsd.org. (47) 00:00.093818 fw.domain > me.domain: 8207 2/0/0 CNAME ftp4.de.freebsd.org., CNAME ftp.leo.org. (77) (DF) 00:00.094539 me.domain > fw.domain: 30226+ [1au] AAAA? ftp.leo.org. (40) 00:00.183988 fw.domain > me.domain: 30226 0/0/0 (29) (DF) 00:05.184504 me.domain > fw.domain: 52418+ [1au] AAAA? ftp.leo.org. (40) 00:05.278765 fw.domain > me.domain: 52418 0/0/0 (29) (DF) 00:15.278043 me.domain > fw.domain: 24089+ [1au] AAAA? ftp.leo.org. (40) 00:15.377019 fw.domain > me.domain: 24089 0/0/0 (29) (DF) 00:35.374320 me.domain > fw.domain: 31178+ [1au] AAAA? ftp.leo.org. (40) 00:35.978176 fw.domain > me.domain: 31178 0/0/0 (29) (DF) 01:15.970823 me.domain > fw.domain: 53751+ [1au] A? ftp.leo.org. (40) 01:16.064579 fw.domain > me.domain: 53751 1/0/0 A 131.159.72.23 (45) (DF) 01:16.065468 me.domain > fw.domain: 56474+ [1au] AAAA? J.ROOT-SERVERS.NET. (47) 01:16.065915 me.domain > fw.domain: 36905+ [1au] AAAA? K.ROOT-SERVERS.NET. (47) 01:16.066172 me.domain > fw.domain: 38356+ [1au] AAAA? L.ROOT-SERVERS.NET. (47) 01:16.066372 me.domain > fw.domain: 395+ [1au] AAAA? M.ROOT-SERVERS.NET. (47) 01:16.066572 me.domain > fw.domain: 54526+ [1au] AAAA? I.ROOT-SERVERS.NET. (47) 01:16.066771 me.domain > fw.domain: 61085+ [1au] AAAA? E.ROOT-SERVERS.NET. (47) 01:16.066986 me.domain > fw.domain: 38040+ [1au] AAAA? D.ROOT-SERVERS.NET. (47) 01:16.068062 me.domain > fw.domain: 35807+ [1au] AAAA? A.ROOT-SERVERS.NET. (47) 01:16.068664 me.domain > fw.domain: 27426+ [1au] AAAA? H.ROOT-SERVERS.NET. (47) 01:16.069117 me.domain > fw.domain: 39377+ [1au] AAAA? C.ROOT-SERVERS.NET. (47) 01:16.069552 me.domain > fw.domain: 11036+ [1au] AAAA? G.ROOT-SERVERS.NET. (47) 01:16.070036 me.domain > fw.domain: 34035+ [1au] AAAA? F.ROOT-SERVERS.NET. (47) 01:16.070476 me.domain > fw.domain: 33542+ [1au] AAAA? B.ROOT-SERVERS.NET. (47) 01:16.157385 fw.domain > me.domain: 56474 0/0/0 (36) (DF) 01:16.160564 fw.domain > me.domain: 36905 0/0/0 (36) (DF) 01:16.172424 fw.domain > me.domain: 38356 0/0/0 (36) (DF) 01:16.176809 fw.domain > me.domain: 395 0/0/0 (36) (DF) 01:16.188828 fw.domain > me.domain: 54526 0/0/0 (36) (DF) 01:16.193810 fw.domain > me.domain: 61085 0/0/0 (36) (DF) 01:16.202584 fw.domain > me.domain: 38040 0/0/0 (36) (DF) 01:16.209829 fw.domain > me.domain: 35807 0/0/0 (36) (DF) 01:16.217073 fw.domain > me.domain: 27426 0/0/0 (36) (DF) 01:16.238637 fw.domain > me.domain: 39377 0/0/0 (36) (DF) 01:16.240081 fw.domain > me.domain: 11036 0/0/0 (36) (DF) 01:16.241823 fw.domain > me.domain: 34035 0/0/0 (36) (DF) 01:16.246842 fw.domain > me.domain: 33542 0/0/0 (36) (DF) As I thought of an IPv6 problem, I compiled a new kernel with IPNET6. That did not help at all, unfortunately. Any ideas?
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