<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman, new york, times, serif;font-size:12pt"><DIV>Hello,</DIV>
<DIV> </DIV>
<DIV>A few of the default settings changed from 9.4.x to 9.6.x</DIV>
<DIV>The appropriate README files, change logs, and BIND ARM will provide details about them.</DIV>
<DIV> </DIV>
<DIV>Below are some options and logging configurations you may want to investigate.</DIV>
<DIV>
<DIV>Ye Ole Disclaimer: Please be sure to understand what these do and the DNS environment these alter before making changes.</DIV></DIV>
<DIV> </DIV>
<DIV>options suggestions: (set some limits)<BR> allow-query { "file-a"; "file-b"; }; #Employ ACLs to limit who can query the server<BR> allow-recursion { "file-a"; "file-b"; }; #Employ ACLs to limit recursion - may or may not be the same files as in the previous statement<BR> blackhole { "file-c"; }; #Employ ACLs to drop abusive queries. Note: This will affect legitimate responses from any networks listed, too. Keep this in mind.<BR> recursive-clients X000; #Understand how many recursive clients the hware should handle at a time<BR> tcp-clients X00; # Understand how many TCP clients should be handled at a time.<BR> clients-per-query X0 ; #Limit the number of
clients-per-query. This helps to limit bogus queries (especially from malware). We use 10.<BR> max-clients-per-query X0 ; # Same as above. That is, we hard set to deal with bogus queries from malware. I believe BIND automagically adjusts this by default.We use 20.<BR> max-cache-size 0 ; #Setting to 0 makes this model older behavior. I believe 9.5+ new default is 32MB. Setting to 0 is unlimited, if memory serves, and is what we want in our environment.<BR></DIV>
<DIV>logging suggestions: (throw away certain things from logging IF you are not interested in them)<BR> channel secure_messages { file "/dev/null"; }; #If "null" is not understood, one can define it using this method.<BR> category security { secure_messages; }; #Fancy way of sending these logs to the garbage can using the previous definition. Setting ACLs generates a lot of log chatter. A good thing while one tweaks ACLs to check the logs. Once ACLs are tweaked, no need to waste CPU and HDD seak time logging data we no longer need = trash can.<BR> category lame-servers { null; }; #Nice info about lame servers, but since we can't fix the Internet = toss to the garbage can for now.<BR> category edns-disabled { null; }; #Again, nice info about EDNS,
but it isn't something our environment needs us to act upon at this time = trash can for now.<BR></DIV>
<DIV>HTH.<BR></DIV>
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<B><SPAN style="FONT-WEIGHT: bold">From:</SPAN></B> Imri Zvik <imriz@inter.net.il><BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B> bind-users@lists.isc.org<BR><B><SPAN style="FONT-WEIGHT: bold">Sent:</SPAN></B> Wednesday, July 8, 2009 2:24:17 PM<BR><B><SPAN style="FONT-WEIGHT: bold">Subject:</SPAN></B> bind 9.6.1 under perform after running for a couple of hours<BR></FONT><BR>
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<P class=MsoNormal style="DIRECTION: ltr; unicode-bidi: embed; TEXT-ALIGN: left">Hi,</P>
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<P class=MsoNormal style="DIRECTION: ltr; unicode-bidi: embed; TEXT-ALIGN: left">After a couple of hours, performance of bind 9.6.1 suddenly drops. While the server remains responsive, the response time increases, the rate of the failed queries increases, and CPU/load average usage increases. Restarting named solves the problem.</P>
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<P class=MsoNormal style="DIRECTION: ltr; unicode-bidi: embed; TEXT-ALIGN: left">I cannot find anything useful in the logs, but a quick search in this mailing list archive shows that other users reported somewhat similar problems with this version of BIND :(</P>
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<P class=MsoNormal style="DIRECTION: ltr; unicode-bidi: embed; TEXT-ALIGN: left">The operating system is Linux (Linux ns1 2.6.18-128.el5 #1 SMP Wed Dec 17 11:41:38 EST 2008 x86_64 x86_64 x86_64 GNU/Linux) , Red Hat Enterprise Linux Server release 5.3 (Tikanga).</P>
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<P class=MsoNormal style="DIRECTION: ltr; unicode-bidi: embed; TEXT-ALIGN: left">Output of named –V:</P>
<P class=MsoNormal style="DIRECTION: ltr; unicode-bidi: embed; TEXT-ALIGN: left">BIND 9.6.1 built with '--enable-threads' '--enable-largefile' '--prefix=/usr/local'</P>
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<P class=MsoNormal style="DIRECTION: ltr; unicode-bidi: embed; TEXT-ALIGN: left">/usr/local/sbin/named: ELF 64-bit LSB executable, AMD x86-64, version 1 (SYSV), for GNU/Linux 2.6.9, dynamically linked (uses shared libs), for GNU/Linux 2.6.9, not stripped</P>
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<P class=MsoNormal style="DIRECTION: ltr; unicode-bidi: embed; TEXT-ALIGN: left">It is important to state that we just upgraded from 9.4.3-P2.</P>
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<P class=MsoNormal style="DIRECTION: ltr; unicode-bidi: embed; TEXT-ALIGN: left">Any ideas?</P>
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