<div dir="ltr">

<p class="MsoNormal"><span style="font-size:10pt;font-family:"Arial","sans-serif"">Hello
guys,</span></p>

<p class="MsoNormal"><span style="font-size:10pt;font-family:"Arial","sans-serif""> </span></p>

<p class="MsoNormal"><span style="font-size:10pt;font-family:"Arial","sans-serif"" lang="EN-US">We are facing to an important issue which is strongly
annoying us on our DNS resolvers. We saw our cache decrease and we got lot of
SERVFAIL/recursion during this period. The only way to solve it is to flush
cache or reboot BIND. Our version is 9.9.9-P8 running on RHEL 6.6. We already
got it 6 times in 1 week on different servers.</span></p>

<p class="MsoNormal"><span style="font-size:10pt;font-family:"Arial","sans-serif"" lang="EN-US">Here some logs when the problem appears :</span></p>

<p class="MsoNormal"><span style="font-size:10pt;font-family:"Arial","sans-serif"" lang="EN-US"> </span></p>

<p class="MsoNormal" style="background:rgb(242,242,242) none repeat scroll 0% 0%"><span style="font-size:10pt;font-family:"Arial","sans-serif";color:black;background:silver none repeat scroll 0% 0%" lang="EN-US">named[10616]:
database: warning: delete_node: dns_rbt_findnode(nsec): partial match</span></p>

<p class="MsoNormal" style="background:rgb(242,242,242) none repeat scroll 0% 0%"><span style="font-size:10pt;font-family:"Arial","sans-serif";color:black;background:silver none repeat scroll 0% 0%" lang="EN-US">named[10616]:
general: warning: checkhints: unable to get root NS rrset from cache: not found</span></p>

<p class="MsoNormal"><span style="font-size:10pt;font-family:"Segoe UI","sans-serif";color:black;background:silver none repeat scroll 0% 0%" lang="EN-US">general: info: sockmgr 0x7f4419f240f0: maximum number of FD events (64)
received</span><span lang="EN-US"></span></p>

<p class="MsoNormal"><span style="font-size:10pt;font-family:"Arial","sans-serif"" lang="EN-US"> </span></p>

<p class="MsoNormal"><span style="font-size:10pt;font-family:"Arial","sans-serif"" lang="EN-US">Below one link to see one cacti’s screen showing the
performance:</span></p><p class="MsoNormal"><span style="font-size:10pt;font-family:"Arial","sans-serif"" lang="EN-US"><a href="https://drive.google.com/file/d/0B3pglqx0sbOiN3ZWQmM3MDdYOTQ/view?usp=sharing" target="_blank">https://drive.google.com/file/<wbr>d/0B3pglqx0sbOiN3ZWQmM3MDdYOTQ<wbr>/view?usp=sharing</a></span></p><p class="MsoNormal"><span style="font-size:10pt;font-family:"Arial","sans-serif"" lang="EN-US"><br></span></p>

<p class="MsoNormal"><span style="font-size:10pt;font-family:"Arial","sans-serif"" lang="EN-US"> </span></p>

<p class="MsoNormal"><span style="font-size:10pt;font-family:"Arial","sans-serif"" lang="EN-US">Do you have any idea to solve it definitively ? Is it
an exploit bug ?</span></p>

<p class="MsoNormal"><span style="font-size:10pt;font-family:"Arial","sans-serif"" lang="EN-US">Thanks for you help.</span></p>

<p class="MsoNormal"><span style="font-size:10pt;font-family:"Arial","sans-serif"" lang="EN-US"> </span></p></div>