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<!DOCTYPE html> <html lang="en-us"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <link rel="icon" href="http://www.zytrax.com/favicon.ico"> <title>ZYTRAX Home Page</title> <meta name="description" content="Zytrax home page, Zytrax DNS and LDAP training and knowledge acquisition, commmunications software delevelopment and consulting."> <meta name="keywords" content="ZYTRAX, DNS, LDAP, Training, knowledge acquisition, software development, consulting, Open Source, Java, C, Ruby">   <style type="text/css">  </style> <style type="text/css" media="print">  </style> <script type="text/javascript">  </script> </head> <body>  <div class="l-b"> <img id="toplogo" src="images/zytrax-com-logo.gif" alt="ZYTRAX.COM LOGO">  <p class="n-t-t"><a href="http://www.zytrax.com/feedback.htm" class="n-t-sr">mail us</a>  |  <a href="http://www.zytrax.com/run/mailpage.php" class="n-t-sr">mail this page</a></p> <div class="n-t0"> <a href="http://www.zytrax.com/Company/contacts.html" class="n-t-sr">contact us</a> </div> <div class="n-t0"> <a href="http://www.zytrax.com/training/" class="n-t-sr">training</a>  |  </div> <div class="n-t0"> <a href="http://www.zytrax.com/tech/" class="n-t-sr">tech stuff</a>  |  <ul class="n-t1-v"> <li class="n-t1-es"><a href="http://www.zytrax.com/tech/" class="t-da">tech stuff</a>  <ul class="n-t2"> <li class="n-t2-e"><a title="collection of technology stuff" href="http://www.zytrax.com/tech/" class="t-da">tech stuff</a></li> <li class="n-t2-es t-da">web stuff <ul class="n-t3"> <li class="n-t3-e"><a title="collection of web based technology stuff" href="http://www.zytrax.com/tech/web/" class="t-da">web stuff</a></li> <li class="n-t3-e"><a title="collection of UA strings for most browsers" href="http://www.zytrax.com/tech/web/browser_ids.htm" class="t-da">browser ids</a></li> <li class="n-t3-e"><a title="collection of mobile UA strings" href="http://www.zytrax.com/tech/web/mobile_ids.html" class="t-da">mobile ids</a></li> <li class="n-t3-e"><a title="our HTML5 page conversion process and thoughts" href="http://www.zytrax.com/tech/css/html5.html" class="t-da">HTML5 Convert</a></li> <li class="n-t3-e"><a title="how we do server-side browser sniffing with apache" href="http://www.zytrax.com/tech/web/browser_sniffing.html" class="t-da">browser sniffing</a></li> <li class="n-t3-e"><a title="apache environmental variables" href="http://www.zytrax.com/tech/web/env_var.htm" class="t-da">apache env's</a></li> <li class="n-t3-e"><a title="apache server side includes - extensive notes and examples" href="http://www.zytrax.com/tech/web/ssi.htm" class="t-da">apache ssi</a></li> <li class="n-t3-e"><a title="our css pop-up/pop-down/flyout menus for Gecko/Opera/MSIE" href="http://www.zytrax.com/tech/css/workarounds.html#popout" class="t-da">pop-outs (css)</a></li> <li class="n-t3-e"><a title="most of those annoying HTML entity codes that we forget all the time" href="http://www.zytrax.com/tech/web/entities.html" class="t-da">html entities</a></li> </ul> </li> <li class="n-t2-es t-da">open guides <ul class="n-t3"> <li class="n-t3-e"><a href="http://www.zytrax.com/books/" class="t-da">open guides</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/books/dns" class="t-da">dns guide</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/books/ldap" class="t-da">ldap guide</a></li> </ul> </li> <li class="n-t2-e"><a title="Decimal to Hexidecimal to Binary conversion - even Octal!" href="http://www.zytrax.com/tech/protocols/hex.html" class="t-da">Dec>Hex>Bin</a></li> <li class="n-t2-es t-da">survival stuff <ul class="n-t3"> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/" title="a series of survival guides for some popular open source software" class="t-da">survival stuff</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/ssl.html" class="t-da">ssl/tls & x.509</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/asn1.html" class="t-da">ASN.1</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/kerberos.html" class="t-da">kerberos</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/postfix.html" class="t-da">postfix</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/cron.html" class="t-da">cron</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/encryption.html" class="t-da">cryptography</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/wxwidgets.html" class="t-da">wxWidgets</a></li> </ul> </li> <li class="n-t2-es t-da">audio stuff <ul class="n-t3"> <li class="n-t3-e"><a title="Pages about Digital Audio, Primers, Calculator, Equalization, FFT" href="http://www.zytrax.com/tech/audio/" class="t-da">audio stuff</a></li> <li class="n-t3-e"><a title="Fundamentals, harmonics, overtone, partials, loudness, ADSR envelopes" href="http://www.zytrax.com/tech/audio/sound.html" class="t-da">sound primer</a></li> <li class="n-t3-e"><a title="Sound digitization, time domain, frequency domain" href="http://www.zytrax.com/tech/audio/digital-sound.html" class="t-da">digital sound</a></li> <li class="n-t3-e"><a title="common frequencies of instruments and in life" href="http://www.zytrax.com/tech/audio/audio.html" class="t-da">frequencies</a></li> <li class="n-t3-e"><a title="equalization principles, octaves, sound metering and FFT" href="http://www.zytrax.com/tech/audio/equalization.html" class="t-da">equalization</a></li> <li class="n-t3-e"><a title="Acoustic caculators for musical notes and FFT bin frequencies" href="http://www.zytrax.com/tech/audio/calculator.html" class="t-da">calculators</a></li> <li class="n-t3-e"><a title="Yet another audio glossary" href="http://www.zytrax.com/tech/audio/glossary.html" class="t-da">glossary</a></li> </ul> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/web/regex.htm" class="t-da">regex stuff</a></li> <li class="n-t2-es t-da">cable stuff <ul class="n-t3"> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/layer_1/" class="t-da">cable stuff</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/layer_1/cables/tech_lan.htm" class="t-da">lan wiring</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/layer_1/cables/mixed.html" class="t-da">lan & telephone</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/layer_1/cables/tech_rs232.htm" class="t-da">rs232 stuff</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/layer_1/cables/heavy.htm" class="t-da">serial primer</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/pc/serial.html" class="t-da">usb 3.2 & firewire</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/pc/monitors.htm" class="t-da">displays</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/layer_1/cables/cables_jacks.htm" class="t-da">modular jacks</a></li> </ul> </li> <li class="n-t2-es t-da">protocol stuff <ul class="n-t3"> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/" class="t-da">protocol stuff</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/tcp.html" class="t-da">tcp-udp-icmp</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/ip-classes.html" class="t-da">ipv4</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/ip-classes.html#calculator" class="t-da">ipv4 Calculator</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/ipv6.html" class="t-da">ipv6</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/ipv6.html#calculator" class="t-da">ipv6 Calculator</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/isdn" class="t-da">isdn-bri</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/lan" class="t-da">802 lan</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/ss7" class="t-da">ss7 & sigtran</a></li> </ul> </li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/pc/" class="t-da">pc stuff</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/wireless/" class="t-da">wireless stuff</a></li> <li class="n-t2-es t-da">css stuff <ul class="n-t3"> <li class="n-t3-e"><a title="collection of css notes and experiences including css menus and css liquid layout" href="http://www.zytrax.com/tech/css/" class="t-da">css stuff</a></li> <li class="n-t3-e"><a title="Notes on our experience with converting to css based liquid layouts - including blow by blow css" href="http://www.zytrax.com/tech/css/layoutnotes.html" class="t-da">css liquid design</a></li> <li class="n-t3-e"><a title="we have used css menus since mid-2003 - blow-by-blow implementation notes" href="http://www.zytrax.com/tech/css/workarounds.html#popout" class="t-da">css menus</a></li> <li class="n-t3-e"><a title="some practical solutions on using css" href="http://www.zytrax.com/tech/css/workarounds.html" class="t-da">css notes</a></li> <li class="n-t3-e"><a title="css shortforms at a glance" href="http://www.zytrax.com/tech/css/shortcut.html" class="t-da">css short-forms</a></li> <li class="n-t3-e"><a title="css selectors and quick overview with links to the W3C specs" href="http://www.zytrax.com/tech/css/syntax.html" class="t-da">css overview</a></li> </ul> </li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/codes.htm" class="t-da">ascii codes</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/data_rates.htm" class="t-da">data rate stuff</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/telephony/" class="t-da">telephony stuff</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/mech/" class="t-da">mech. stuff</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/protocols/hex.html" class="t-da">Dec>Hex>Bin</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/lang/" class="t-da">language stuff</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/electronics/" class="t-da">electronic stuff</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/rfcs/" class="t-da">rfc stuff</a></li> </ul> </li> <li class="n-t1-e"><a href="http://www.zytrax.com/security/" class="t-da">Security</a></li> </ul> </div>  </div>  <div class="l-c">  <h1 class="t-r">Welcome to ZyTrax</h1> <p><script type="text/javascript">document.write(showtime());</script></p> <h2>Zytrax Training</h2> <p><a href="training/" class="t-db">ZYTRAX Training</a> focuses on Knowledge Acquisition and Transfer. We provide high quality courses in DNS and LDAP where our subject-matter experts are unique in their fields. <a href="http://www.amazon.com/Pro-DNS-BIND-Ron-Aitchison/dp/1590594940" class="t-db">We've even written books on this stuff</a>. We don't simply teach courses, which is what most of our competition does, we transfer the knowledge of our subject-matter experts to our students. Our experts are passionate about their subjects. And yes, it is possible for (relatively) normal human beings to get passionate about DNS, or LDAP. There is a big difference being taught by someone who feels strongly about their subject. At the end of a course our students don't just know the material, they understand it. Your organization wins all round. <a href="training/" class="t-db">We provide a range of standard public and on-site courses and can customize material to meet your needs</a>.</p> <h2>Zytrax Tech Stuff</h2> <p>The ZYTRAX <a href="tech/" class="t-db">Tech Stuff</a> section is a collection of technical information that we have found useful over the years and which is provided as a free service to the community. We ask in return that if you spot errors or omissions you drop us an email. We always answer in the same spirit that you write to us.</p> <h2>Zytrax Open Source</h2> <p>ZYTRAX has been an advocate of Open Source solutions for many years, we have added a second in our series of whimsically named <i>Rocket Scientist Guides</i> <a href="books/ldap" class="t-db">LDAP for Rocket Scientists</a>. The first in the series, <a href="books/dns" class="t-db">DNS for Rocket Scientists</a>, has already proven immensely popular and is being used hundreds of thousand of times per month.</p> <h2>Other Stuff</h2> <p>If you are curious about these things you can find out why we called the company <a href="zytrax_name.htm" class="t-db">ZyTrax</a>. And some information <a href="about_site.htm" class="t-db">about the technology used on our web site</a> if that kind of stuff appeals to you.</p> </div> <div class="l-l-fp"> <div class="n-l-fp t-r"> <p class="c-g t-b t-o t-r">Services</p> <span class="c-g t-b t-r"></span> <p><a href="http://www.zytrax.com/Company/">Company</a></p> <p><a href="http://www.zytrax.com/training/">training</a></p> <p><a href="http://www.zytrax.com/consulting/">consulting</a></p> <p><a href="http://www.zytrax.com/tech/">tech stuff</a></p> <p><a href="http://www.zytrax.com/books/">open guides</a></p> <p class="c-g t-b t-o m-h5">Page<p> <a class="a-n" href="http://www.zytrax.com/feedback.htm"><img class="w-32" title="Page comment feature" src="http://www.zytrax.com/images/mail.png" alt="email us"></a> <a class="a-n" href="http://www.zytrax.com/run/mailpage.php"><img class="w-32" title="Send to a friend" src="http://www.zytrax.com/images/mailfriend.png" alt="Send to a friend feature"></a> <a class="a-n" href="#" onclick="window.print();return false;"><img class="w-32" title="print page" src="http://www.zytrax.com/images/printpage.png" alt="print this page"></a> <a class="a-n" title="View page full width - suppresses left and right hand menus" href="http://www.zytrax.com/?pf=yes"><img class="w-32" src="http://www.zytrax.com/images/fullwidth.png" alt="Display full width page"></a> <a class="a-n" href="#" onclick="fontchange('d');return false;"><img class="w-32" title="Decrease font size" src="http://www.zytrax.com/images/smaller.png" alt="Decrease font size"></a> <a class="a-n" href="#" onclick="fontchange('i');return false;"><img class="w-32" title="Increase font size" src="http://www.zytrax.com/images/bigger.png" alt="Increase font size"></a> <p class="c-g t-b t-o">Site</p> <a class="a-n" href="http://www.zytrax.com/about_site.htm#css"><img class="w-32" src="http://www.zytrax.com/images/css.png" alt="CSS Technology"></a> <a class="a-n" href="http://www.zytrax.com/security/spf.html"><img title="SPF Record Conformant Domain" class="w-32" src="http://www.zytrax.com/images/spf.png" alt="SPF Record Conformant Domain"></a> <p class="t-r p-b-h">If you are happy it's OK - but your browser is giving a less than optimal experience on our site. You could, at no charge, upgrade to a W3C STANDARDS COMPLIANT browser such as <a href="http://www.mozilla.org" class="t-db">Mozilla</a></p> </div> </div> <div class="l-r-fp">   <p class="c-g t-b t-o m-h8">Search</p> <form class="f-b-n" method="get" action="http://www.google.com/custom" target="_top"> <table> <tr> <td style="white-space: nowrap"> <input type="hidden" name="domains" value="www.zytrax.com"> <input class="b-lg" type="text" name="q" size="16" maxlength="255" value=""> </td></tr> <tr> <td style="white-space: nowrap"> <table> <tr> <td> <input type="radio" name="sitesearch" value="" checked="checked"><span class="t-s">web</span> </td> <td> <input type="radio" name="sitesearch" value="www.zytrax.com" ><span class="t-s">zytrax.com</span> </td> </tr> </table> <input class="b-lg" type="submit" name="sa" value="Google Search"> <input type="hidden" name="client" value="pub-9419480011552853"> <input type="hidden" name="forid" value="1"> <input type="hidden" name="ie" value="ISO-8859-1"> <input type="hidden" name="oe" value="ISO-8859-1"> <input type="hidden" name="safe" value="active"> <input type="hidden" name="cof" value="GALT:#008000;GL:1;DIV:#336699;VLC:663399;AH:center;BGC:FFFFFF;LBGC:336699;ALC:0000FF;LC:0000FF;T:000000;GFNT:0000FF;GIMP:0000FF;LH:50;LW:355;L:http://www.zytrax.com/images/zytrax-info-google.gif;S:http://www.zytrax.com/tech;FORID:1;"> <input type="hidden" name="hl" value="en"> </td></tr></table> </form>   <table class="p-m-s"> <tr class="g-h-n t-b"> <td>Stuff Column</td> </tr> <tr > <td> You may find some of these things interesting..or then again you may not... <hr> <u>We've Moved</u><br> To improve our service we are now hosted by <a href="https://javapipe.com" target="_blank" class="t-dd">javapipe.com</a> in some far off land. Very happy ... so far. Thanks. <hr> <u>Fighting Back</u><br> Click any SPF button to <a href="http://www.zytrax.com/security/spf.html" class="t-db">read about our policy</a> and <a href="http://www.zytrax.com/books/dns/ch9/spf.html" class="t-db">how to define a DNS SPF record</a>. We urge you to publish SPF records to reduce SPAM and stop identity theft. You also might want to consider <a href="http://www.zytrax.com/books/dns/ch9/dkim.html" class="t-db">DKIM</a>. <hr> <u>Open Source - it's complicated</u><br> Great software. Legal and free. <a href="http://incubator.apache.org/openofficeorg/" class="t-db">OpenOffice</a> has moved to the Apache foundation where they are figuring out how to move it forward. In the meantime we, like many others, have moved to <a href="http://www.libreoffice.org/" class="t-db">LibreOffice</a>. But it's all so serious now. We remember when Ethereal's (now <a href="http://www.wireshark.org/" class="t-db">wireshark</a>) marketing slogan was "Sniffing the glue that holds the Internet together". Now that was fun. But fun is soooo last century. <hr> <u>HTML 5</u><br> There was a time when we got excited about HTML and CSS standards. Validated everything that moved. Religiously. But the world was young then and we believed what the W3C told us. HTML 5 is a joke. Whatever someone thinks it is today, or yesterday, or last week. Meh. <hr> </td> </tr> </table> </div> <div class="l-f">  <table> <tr> <td class="p-f-s t-l"> Copyright © 1994 - 2024 ZyTrax, Inc.<br> All rights reserved. <a href="http://www.zytrax.com/legal.html" class="p-f-s">Legal</a> and <a href="http://www.zytrax.com/privacy.html" class="p-f-s">Privacy</a> </td> <td class="t-c"><a href="https://www.zytrax.com" target="_blank" class="p-f-s">site by zytrax</a><br> <a href="https://www.javapipe.com" target="_blank" class="p-f-s">hosted by javapipe.com</a></td> <td class="p-f-s t-r"> <a href="javascript:mailus('web-master','zytrax.com','About Web site')" class="p-f-s">web-master at zytrax</a><br> Page modified: February 10 2022. </td> </tr> </table> </div> </body> </html>