<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_ym19_1_1462271913527_9282"><span id="yui_3_16_0_ym19_1_1462271913527_9335">Hello,</span></div><div id="yui_3_16_0_ym19_1_1462271913527_9671"><span id="yui_3_16_0_ym19_1_1462271913527_9335"><br></span></div><div dir="ltr" id="yui_3_16_0_ym19_1_1462271913527_9622"><span id="yui_3_16_0_ym19_1_1462271913527_9335">In my named.log I can see a lot of SERVFAIL/REFUSED unexpected RCODE messages. Most of the time someone tries to resolve a PTR</span></div><div id="yui_3_16_0_ym19_1_1462271913527_9808" dir="ltr"><span id="yui_3_16_0_ym19_1_1462271913527_9335"><br></span></div><div id="yui_3_16_0_ym19_1_1462271913527_9737" dir="ltr"><span id="yui_3_16_0_ym19_1_1462271913527_9335">I can see an average of 10 messages per second like these<br></span></div><div id="yui_3_16_0_ym19_1_1462271913527_9750" dir="ltr"><span id="yui_3_16_0_ym19_1_1462271913527_9335">May  3 10:46:26 dns named[7228]: REFUSED unexpected RCODE resolving 'x.204.99.116.in-addr.arpa/PTR/IN': 203.113.131.x#53<br id="yui_3_16_0_ym19_1_1462271913527_9755">May  3 10:46:26 dns named[7228]: SERVFAIL unexpected RCODE resolving 'x.16.165.88.in-addr.arpa/PTR/IN': 193.0.9.x#53<br id="yui_3_16_0_ym19_1_1462271913527_9756"></span></div><div id="yui_3_16_0_ym19_1_1462271913527_9817" dir="ltr"><br><span id="yui_3_16_0_ym19_1_1462271913527_9335"></span></div><div id="yui_3_16_0_ym19_1_1462271913527_9856" dir="ltr"><span id="yui_3_16_0_ym19_1_1462271913527_9335">The PTR records don't belong to me and the remote DNS servers are located around the world.</span></div><div id="yui_3_16_0_ym19_1_1462271913527_9906" dir="ltr"><br><span id="yui_3_16_0_ym19_1_1462271913527_9335"></span></div><div id="yui_3_16_0_ym19_1_1462271913527_9907" dir="ltr"><span id="yui_3_16_0_ym19_1_1462271913527_9335">Does anyone has an understanding of why I receive these type of requests ? Why do they query my DNS servers ?</span></div><div id="yui_3_16_0_ym19_1_1462271913527_9961" dir="ltr"><br><span id="yui_3_16_0_ym19_1_1462271913527_9335"></span></div><div id="yui_3_16_0_ym19_1_1462271913527_9962" dir="ltr"><span id="yui_3_16_0_ym19_1_1462271913527_9335">Thank you</span></div><br></div></body></html>