{"id":109,"date":"2004-10-10T07:54:25","date_gmt":"2004-10-10T11:54:25","guid":{"rendered":"http:\/\/kev.needham.ca\/blog\/?p=109"},"modified":"2004-10-10T07:54:25","modified_gmt":"2004-10-10T11:54:25","slug":"stupid-caching-rules","status":"publish","type":"post","link":"https:\/\/kev.needham.ca\/index.php\/2004\/10\/10\/stupid-caching-rules\/","title":{"rendered":"stupid OS tricks"},"content":{"rendered":"<p>Apparently, XP will cache nameserver lookup errors. This is really stupid. I was making some changes last night and adding some entries to zones. I forgot to restart named, and was getting errors when attempting to connect to the host by name. I restarted named, still no joy, and then I started browsing logs to find out what I had mis-configured. I spent five minutes looking at everything before realizing named was fine, it was the client that had the issue. <\/p>\n<p>It was only five minutes, but I&#8217;ll never get it back. I wonder what genius thought that was a good idea? I realize the client is acting like it&#8217;s own nameserver, as it uses the TTL from the domain to refresh the info, and have no problem with that. It&#8217;s the caching of errors which is stupid.<\/p>\n<p><font face=\"Courier, Courier New\">ipconfig \/flushdns<\/font> is your friend, should you ever run into this. <font face=\"Courier, Courier New\">ipconfig \/displaydns<\/font> will show a complete list of all the info in your DNS cache. I was surprised by how much info was in the cache &#8211; there&#8217;s potential there for people to track where you&#8217;ve been going from the cached lookups if you leave your computer on all the time. Clearing all the normal stuff (history, cookies, file cache, etc.) won&#8217;t clear the resolver cache, which contains a list of everywhere you and your browser have gone.  Food for thought.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Apparently, XP will cache nameserver lookup errors. This is really stupid. I was making some changes last night and adding some entries to zones. I forgot to restart named, and was getting errors when attempting to connect to the host by name. I restarted named, still no joy, and then I started browsing logs to [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[],"class_list":["post-109","post","type-post","status-publish","format-standard","hentry","category-general"],"_links":{"self":[{"href":"https:\/\/kev.needham.ca\/index.php\/wp-json\/wp\/v2\/posts\/109","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kev.needham.ca\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kev.needham.ca\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kev.needham.ca\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kev.needham.ca\/index.php\/wp-json\/wp\/v2\/comments?post=109"}],"version-history":[{"count":0,"href":"https:\/\/kev.needham.ca\/index.php\/wp-json\/wp\/v2\/posts\/109\/revisions"}],"wp:attachment":[{"href":"https:\/\/kev.needham.ca\/index.php\/wp-json\/wp\/v2\/media?parent=109"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kev.needham.ca\/index.php\/wp-json\/wp\/v2\/categories?post=109"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kev.needham.ca\/index.php\/wp-json\/wp\/v2\/tags?post=109"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}