You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@trafficserver.apache.org by di...@apache.org on 2009/12/17 22:32:18 UTC
svn commit: r891921 -
/incubator/trafficserver/site/trunk/docs/admin/files.htm
Author: dianes
Date: Thu Dec 17 21:32:18 2009
New Revision: 891921
URL: http://svn.apache.org/viewvc?rev=891921&view=rev
Log:
mods to remap.config
Modified:
incubator/trafficserver/site/trunk/docs/admin/files.htm
Modified: incubator/trafficserver/site/trunk/docs/admin/files.htm
URL: http://svn.apache.org/viewvc/incubator/trafficserver/site/trunk/docs/admin/files.htm?rev=891921&r1=891920&r2=891921&view=diff
==============================================================================
--- incubator/trafficserver/site/trunk/docs/admin/files.htm (original)
+++ incubator/trafficserver/site/trunk/docs/admin/files.htm Thu Dec 17 21:32:18 2009
@@ -32,7 +32,7 @@
<h2>
<a name="69422">bypass.config</a></h2>
- <p> The <code> bypass.config</code> file contains static bypass rules that Traffic Server uses in transparent proxy caching mode. <em> Static</em> bypass rules instruct Traffic Server to bypass certain incoming client requests so they are served by the origin server. The <code>bypass.config</code> file also accepts<em> </em><a href="#62813"><em>Dynamic Deny Bypass Rules</em></a>.</p>
+ <p> The <code> bypass.config</code> file contains static bypass rules that Traffic Server uses in transparent proxy caching mode. <em> Static</em> bypass rules instruct Traffic Server to bypass certain incoming client requests so they are served by the origin server. The <code>bypass.config</code> file also accepts <a href="#62813">Dynamic Deny Bypass Rules</a>.</p>
<p>You can configure three types of static bypass rules: </p>
<ul>
@@ -80,7 +80,7 @@
</table>
<h4>
<a name="62813">Dynamic Deny Bypass Rules</a> </h4>
- <p>In addition to static bypass rules, the <code>bypass.confi</code>g file also accepts <em>dynamic</em> <em>deny </em>bypass rules that prevent Traffic Server from bypassing certain incoming client requests dynamically (a deny bypass rule can prevent Traffic Server from bypassing itself). Dynamic deny bypass rules can be source, destination, or source/destination and have the following format: <br />
+ <p>In addition to static bypass rules, the <code>bypass.confi</code>g file also accepts <em>dynamic deny </em>bypass rules that prevent Traffic Server from bypassing certain incoming client requests dynamically (a deny bypass rule can prevent Traffic Server from bypassing itself). Dynamic deny bypass rules can be source, destination, or source/destination and have the following format: <br />
<code>deny_dyn_bypass src <em>ipaddress</em> | dst <em>ipaddress</em> | src <em>ipaddresss</em> AND <em>ipaddress</em></code> </p>
<p>For a description of the options, refer to the table above. For the dynamic deny bypass rules to work, you must set the variable <code><i>proxy.config.arm.bypass_dynamic_enabled</i></code> to <code>1</code> in the <code>records.config</code> file. </p>
@@ -213,7 +213,7 @@
<h2>
<a name="220539">congestion.config</a> </h2>
- <p>The <code>congestion.config</code> file enables you to configure Traffic Server to stop forwarding HTTP requests to origin servers when they become congested, and then send the client a message to retry the congested origin server later. After you modify the <code>congestion.control</code> file, navigate to the Traffic Server<code> bin</code> directory; then run the <code>traffic_line -x</code> command to apply changes. When you apply the changes to a node in a cluster, Traffic Server automatically applies the changes to all other nodes in the cluster. Traffic Server uses the <code>congestion.config</code> file only if you enable the <a href="http.htm#UsingCongestionControl"><em>Congestion Control</em></a> option.</p>
+ <p>The <code>congestion.config</code> file enables you to configure Traffic Server to stop forwarding HTTP requests to origin servers when they become congested, and then send the client a message to retry the congested origin server later. After you modify the <code>congestion.control</code> file, navigate to the Traffic Server<code> bin</code> directory; then run the <code>traffic_line -x</code> command to apply changes. When you apply the changes to a node in a cluster, Traffic Server automatically applies the changes to all other nodes in the cluster. Traffic Server uses the <code>congestion.config</code> file only if you enable the <a href="http.htm#UsingCongestionControl">Congestion Control</a> option.</p>
<p>You can create rules in the <code>congestion.config</code> file to specify: </p>
<ul>
<li>Which origin servers Traffic Server tracks for congestion.</li>
@@ -312,7 +312,7 @@
</tr>
<tr>
<td><p><i><code>error_page</code></i></p></td>
- <td><p>The error page sent to the client when a server is congested. You must enclose the value in quotes; the default value is <code> "congestion#retryAfter"</code>.<br />The error page is sent only if the <code>Custom Responses</code> option is enabled (refer to <a href="options.htm#125023"><em>HTTP Responses</em></a>).</p></td>
+ <td><p>The error page sent to the client when a server is congested. You must enclose the value in quotes; the default value is <code> "congestion#retryAfter"</code>.<br />The error page is sent only if the <code>Custom Responses</code> option is enabled (refer to <a href="options.htm#125023">HTTP Responses</a>).</p></td>
</tr>
<tr>
<td><p><i><code>congestion_scheme</code></i></p></td>
@@ -327,7 +327,7 @@
<p>You can use one or more tags in a rule, but each tag must have one value only. If you specify no tags in the rule, then Traffic Server uses default values. </p>
<p>You can override any of the default tag values by adding configuration variables at the end of <code>records.config</code> as follows: <br />
<code>CONFIG proxy.config.http.congestion_control.default.<em>tag</em> INT|STRING <em>value</em></code> <br />
- where <code><i><b>tag</b></i></code> is one of the tags described in the table under <a href="#220539"><em>congestion.config</em></a> and <code><i><b>value</b></i></code> is the value you want to use.</p>
+ where <code><i><b>tag</b></i></code> is one of the tags described in the table under <a href="#220539">congestion.config</a> and <code><i><b>value</b></i></code> is the value you want to use.</p>
<p>For example: <br /><code>CONFIG<br />
proxy.config.http.congestion_control.default.congestion_scheme STRING per_host</code> </p>
<p><strong>IMPORTANT: </strong>Rules in the <code>congestion.config</code> file override the following variables in the <code>records.config</code> file: </p>
@@ -438,8 +438,8 @@
<code>dest_ip=0.0.0.0-255.255.255.255 action=lda</code></p>
<h2>
<a name="139053">hosting.config</a> </h2>
- <p>The <code>hosting.config</code> file enables you to assign cache partitions to specific origin servers and/or domains so that you can manage cache space efficiently and restrict disk usage. For step-by-step instructions on partitioning the cache according to origin servers and/or domains, refer to <a href="cache.htm"><em>Partitioning the Cache According to Origin Server or Domai</em>n</a>.
-<br />Before you can assign cache partitions to specific origin servers and/or domains, you must first partition your cache according to size and protocol in the <code>partition.config</code> file. For step-by-step instructions about partitioning your cache, refer to <a href="cache.htm"><em>Partitioning the Cache</em></a>. For a description of the <code>partition.config</code> file, refer to <a href="#50072"><em>partition.config</em></a>. </p>
+ <p>The <code>hosting.config</code> file enables you to assign cache partitions to specific origin servers and/or domains so that you can manage cache space efficiently and restrict disk usage. For step-by-step instructions on partitioning the cache according to origin servers and/or domains, refer to <a href="cache.htm">Partitioning the Cache According to Origin Server or Domain</a>.
+<br />Before you can assign cache partitions to specific origin servers and/or domains, you must first partition your cache according to size and protocol in the <code>partition.config</code> file. For step-by-step instructions about partitioning your cache, refer to <a href="cache.htm">Partitioning the Cache</a>. For a description of the <code>partition.config</code> file, refer to <a href="#50072">partition.config</a>. </p>
<p>After you modify <code>hosting.config, </code> navigate to the Traffic Server<code> bin</code> directory and run the <code>traffic_line -x</code> command to apply the changes. When you apply the changes to a node in a cluster, Traffic Server automatically applies the changes to all other nodes in the cluster. </p>
<p><strong>IMPORTANT:</strong> The partition configuration must be the same on all nodes in a cluster. </p>
<h3>
@@ -528,7 +528,7 @@
<h2>
<a name="149839">logs.config</a></h2>
<p>The <code>logs.config</code> file establishes and formats <em>traditional</em> custom transaction log files. <br />
- Although Traffic Server supports traditional custom logging, you should use the more versatile XML-based custom logging. Refer to <a href="log.htm"><em>Using the Custom Format</em></a>, and <a href="#131440"><em>logs_xml.config</em></a>. If you opt to use traditional custom logging instead of the more versatile XML-based custom logging, then you must enable the traditional custom logging option manually. Refer to <a href="log.htm"><em>Support for Traditional Custom Logging</em></a>. </p>
+ Although Traffic Server supports traditional custom logging, you should use the more versatile XML-based custom logging. Refer to <a href="log.htm">Using the Custom Format</a>, and <a href="#131440"><em>l</em>ogs_xml.config</a>. If you opt to use traditional custom logging instead of the more versatile XML-based custom logging, then you must enable the traditional custom logging option manually. Refer to <a href="log.htm">Support for Traditional Custom Logging</a>. </p>
<p><strong>IMPORTANT: </strong>After you modify <code>logs.config</code>, navigate to the Traffic Server<code> bin</code> directory and run the <code>traffic_line -x</code> command to apply changes. When you apply the changes to a node in a cluster, Traffic Server automatically applies the changes to all other nodes in the cluster. </p>
<h3>
@@ -559,7 +559,7 @@
</tr>
<tr>
<td><p><i><code> format string</code> </i></p></td>
- <td><p>Identifies the <code> printf</code> -style format string specifying the field symbols to be displayed and how they should look in ASCII. Refer to <a href="logfmts.htm"><em> Appendix D</em></a> for a list of the available field symbols and their meanings. Field symbols are indicated by %<<code> field_symbol</code> > format; for example, to indicate that <code> chi</code> is the client host IP and not the string <code> chi</code> to be printed, enter %<code> <chi></code> . </p></td>
+ <td><p>Identifies the <code> printf</code> -style format string specifying the field symbols to be displayed and how they should look in ASCII. Refer to the <a href="logfmts.htm"> Appendix</a> for a list of the available field symbols and their meanings. Field symbols are indicated by %<<code> field_symbol</code> > format; for example, to indicate that <code> chi</code> is the client host IP and not the string <code> chi</code> to be printed, enter %<code> <chi></code> . </p></td>
</tr>
<tr>
<td><p><i><code> file name</code> </i></p></td>
@@ -634,7 +634,7 @@
</tr>
<tr>
<td><p><code><Format = "valid_format_specification"/></code></p></td>
- <td><p>Required. A valid format specification is a printf-style string describing each log entry when formatted for ASCII output. Use <code> %< <em> field</em> ></code> as a placeholder for valid field names. For more information, refer to <a href="logfmts.htm#66912"><em> Custom Logging Fields</em></a>. </p>
+ <td><p>Required. A valid format specification is a printf-style string describing each log entry when formatted for ASCII output. Use <code> %< <em> field</em> ></code> as a placeholder for valid field names. For more information, refer to <a href="logfmts.htm#66912"> Custom Logging Fields</a>. </p>
<p>The specified field can be one of the following types:
</p><ul> <li>Simple - for example, <code>%<cqu><br />
</code></li><li>A field within a container, such as an HTTP header or a statistic. Fields of this type have the syntax: '<code> %<{ <em> field</em> } <em> container</em> ></code> '.</li><li>
@@ -667,7 +667,7 @@
<tr>
<td><p><code><Condition = "valid_log_field valid_operator valid_comparison_value"/></code></p></td>
<td><p>Required. This field contains the following elements:</p>
- <p><code> <b>valid_log_field</b></code> - the field that will be compared against the given value. For more information, refer to <a href="logfmts.htm#63460"><em>Logging Format Cross-Reference</em></a>.</p>
+ <p><code> <b>valid_log_field</b></code> - the field that will be compared against the given value. For more information, refer to <a href="logfmts.htm#63460">Logging Format Cross-Reference</a>.</p>
<p><code> <b>valid_operator_field</b></code> - any one of the following: <code> MATCH</code> , <code> CASE_INSENSITIVE_MATCH</code> , <code> CONTAIN</code> , <code> CASE_INSENSITIVE_CONTAIN</code>.
</p><ul>
<li><code>MATCH</code> is true if the field and value are identical (case-sensitive). </li>
@@ -697,7 +697,7 @@
<tr>
<td><p><code><Filename = "file_name"/></code></p></td>
<td><p>Required. The filename to which the given log file is written on the local file system or on a remote collation server. No local log file will be created if you fail to specify this tag. All filenames are relative to the default logging directory.</p>
- <p>If the name does not contain an extension (for example, <code> squid</code>), then the extension <code> .log</code> is automatically appended to it for ASCII logs and <code> .blog</code> for binary logs (refer to <a href="files.htm#0_73225"><em><Mode = "valid_logging_mode"/></em></a>). If you do not want an extension to be added, then end the filename with a single (.) dot (for example: <code> squid.</code> ).</p></td>
+ <p>If the name does not contain an extension (for example, <code> squid</code>), then the extension <code> .log</code> is automatically appended to it for ASCII logs and <code> .blog</code> for binary logs (refer to <a href="files.htm#0_73225">Mode = "valid_logging_mode"</a>). If you do not want an extension to be added, then end the filename with a single (.) dot (for example: <code> squid.</code> ).</p></td>
</tr>
<tr>
<td><p><code><a name="0_73225"></a><Mode = "valid_logging_mode"/></code></p></td>
@@ -820,7 +820,7 @@
<li>Set up parent cache hierarchies, with multiple parents and parent failover</li>
<li>Configure selected URL requests to bypass parent proxies </li>
</ul>
- <p>Traffic Server uses the <code>parent.config</code> file only when the parent caching option is enabled; refer to <a href="hier.htm"><em>Configuring Traffic Server to Use a Parent Cache</em></a>. </p>
+ <p>Traffic Server uses the <code>parent.config</code> file only when the parent caching option is enabled; refer to <a href="hier.htm"><i>Configuring Traffic Server to Use a Parent Cache</i></a>. </p>
<p><strong>IMPORTANT:</strong> After you modify the <code>parent.config</code> file, navigate to the Traffic Server<code> bin</code> directory and run the <code>traffic_line -x</code> command to apply the changes. When you apply the changes to a node in a cluster, Traffic Server automatically applies the changes to all other nodes in the cluster. </p>
<h3>
@@ -923,8 +923,8 @@
<p>Every line in the <code>parent.config</code> file must contain either a <code>parent=</code> or <code>go_direct=</code> directive.</p>
<h2>
<a name="50072">partition.config</a> </h2>
- <p>The <code>partition.config</code> file lets you manage your cache space more efficiently and restrict disk usage by creating cache partitions of different sizes for specific protocols. You can further configure these partitions to store data from certain origin servers and/or domains in the <code>hosting.config</code> file (refer to <a href="#139053"><em>hosting.config</em></a>). </p>
- <p><strong>IMPORTANT: </strong> The partition configuration must be the same on all nodes in a cluster. You must stop Traffic Server before you change the cache partition size and protocol assignment. For step-by-step instructions about partitioning the cache, refer to <a href="cache.htm"><em>Partitioning the Cache</em></a>. </p>
+ <p>The <code>partition.config</code> file lets you manage your cache space more efficiently and restrict disk usage by creating cache partitions of different sizes for specific protocols. You can further configure these partitions to store data from certain origin servers and/or domains in the <code>hosting.config</code> file (refer to <a href="#139053">hosting.config</a>). </p>
+ <p><strong>IMPORTANT: </strong> The partition configuration must be the same on all nodes in a cluster. You must stop Traffic Server before you change the cache partition size and protocol assignment. For step-by-step instructions about partitioning the cache, refer to <a href="cache.htm">Partitioning the Cache</a>. </p>
<h3>
<a name="115449">Format</a> </h3>
<p>For each partition you want to create, enter a line with the following format: <br />
@@ -1137,12 +1137,12 @@
<td><p><code><i>proxy.config.admin.admin_password</i></code></p>
<p><code>STRING</code></p></td>
<td></td>
- <td>Specifies the encrypted administrator password that controls access to Traffic Manager. The format can be recreated with:<br>
+ <td>Specifies the encrypted administrator password that controls access to Traffic Manager. The format can be recreated with:<br />
<code>
-#!/usr/bin/php<br>
-<?php<br>
-$foo = md5('admin',true); <br>
-echo strtoupper(substr(bin2hex($foo),0,23)) . "\n";<br>
+#!/usr/bin/php<br />
+<?php<br />
+$foo = md5('admin',true); <br />
+echo strtoupper(substr(bin2hex($foo),0,23)) . "\n";<br />
?></code></td>
</tr>
<tr>
@@ -1461,7 +1461,7 @@
<td><p><code><i>proxy.config.http.congestion_control.enabled</i></code></p>
<p><code>INT</code></p></td>
<td><p><code>0</code></p></td>
- <td><p>Enables (1) or disables (0) the congestion control option, which configures Traffic Server to stop forwarding HTTP requests to origin servers when they become congested. Traffic Server sends the client a message to retry the congested origin server later. Refer to <a href="http.htm#UsingCongestionControl"><i>Using Congestion Control</i></a>.</p></td>
+ <td><p>Enables (1) or disables (0) the congestion control option, which configures Traffic Server to stop forwarding HTTP requests to origin servers when they become congested. Traffic Server sends the client a message to retry the congested origin server later. Refer to <a href="http.htm#UsingCongestionControl">Using Congestion Control</a>.</p></td>
</tr>
<tr>
<td rowspan=="1" colspan="3"><p><strong> Negative Response Caching</strong></p></td>
@@ -1836,7 +1836,7 @@
<p><code>INT</code></p></td>
<td><p><code>0</code></p></td>
<td><p>Enables (1) or disables (0) DNS server selection.<br />
- When enabled, Traffic Server refers to the <code> splitdns.config</code> file for the selection specification. Refer to <a href="secure.htm#ConfiguringDNSServerSelectionSplit"><em>Configuring DNS Server Selection (Split DNS)</em></a>.</p></td>
+ When enabled, Traffic Server refers to the <code> splitdns.config</code> file for the selection specification. Refer to <a href="secure.htm#ConfiguringDNSServerSelectionSplit">Configuring DNS Server Selection (Split DNS)</a>.</p></td>
</tr>
<tr>
<td><p><code><i>proxy.config.dns.splitdns.def_domain </i></code></p>
@@ -2115,7 +2115,7 @@
2 = This host is a collation client and sends entries using standard formats to the collation server.<br />
3 = This host is a collation client and sends entries using the traditional custom formats to the collation server.<br />
4 = This host is a collation client and sends entries that use both the standard and traditional custom formats to the collation server.</p>
- <p>For information on sending XML-based custom formats to the collation server, refer to <a href="files.htm#131440"><em>logs_xml.config</em></a>.</p>
+ <p>For information on sending XML-based custom formats to the collation server, refer to <a href="files.htm#131440">logs_xml.config</a>.</p>
<p><b>Note:</b> Although Traffic Server supports traditional custom logging, you should use the more versatile XML-based custom formats.</p></td>
</tr>
<tr>
@@ -2269,7 +2269,7 @@
<p><code>INT</code></p></td>
<td><p><code>0</code></p></td>
<td><p>Enables (1) or disables (0) the SSL termination option.</p>
- <p>Refer to <a href="secure.htm#UsingSSLTermination"><em>Using SSL Termination</em></a>.</p></td>
+ <p>Refer to <a href="secure.htm#UsingSSLTermination">Using SSL Termination</a>.</p></td>
</tr>
<tr>
<td><p><code><i>proxy.config.ssl.SSLv2</i></code></p>
@@ -2413,7 +2413,7 @@
<td><p><code>0</code></p></td>
<td><p>Sets ICP mode for hierarchical caching:</p>
<p>0 = disables ICP.<br />1 = allows Traffic Server to receive ICP queries only.<br />2 = allows Traffic Server to send and receive ICP queries.</p>
- <p>Refer to <a href="hier.htm#ICPPeering"><em>ICP Peering</em></a>.</p></td>
+ <p>Refer to <a href="hier.htm#ICPPeering">ICP Peering</a>.</p></td>
</tr>
<tr>
<td><p><code><i>proxy.config.icp.icp_interface </i></code></p>
@@ -2553,7 +2553,7 @@
<li>Redirect HTTP requests permanently or temporarily without Traffic Server having to contact any origin servers
</li>
</ul>
- <p>Refer to <a href="reverse.htm"><em>Reverse Proxy and HTTP Redirects</em></a>, for information about redirecting HTTP requests and using reverse proxy. </p>
+ <p>Refer to <a href="reverse.htm">Reverse Proxy and HTTP Redirects</a>, for information about redirecting HTTP requests and using reverse proxy. </p>
<p><strong>IMPORTANT: </strong>After you modify the <code>remap.config</code> file, navigate to the Traffic Server<code> bin</code> directory; then run the <code>traffic_line -x</code> command to apply the changes. When you apply the changes to a node in a cluster, Traffic Server automatically applies the changes to all other nodes in the cluster. </p>
<h3>
<a name="133269">Format</a> </h3>
@@ -2569,17 +2569,18 @@
<p><code> map</code> --translates an incoming request URL to the appropriate origin server URL.</p>
<p><code> reverse_map</code> --translates the URL in origin server redirect responses to point to the Traffic Server. </p>
<p><code> redirect</code> --redirects HTTP requests permanently without having to contact the origin server. Permanent redirects notify the browser of the URL change (by returning an HTTP status code 301) so that the browser can update bookmarks.</p>
- <p><code> redirect_temporary</code> --redirects HTTP requests temporarily without having to contact the origin server. Temporary redirects notify the browser of the URL change for the current request only (by returning an HTTP status code 307).</p></td>
+ <p><code> redirect_temporary</code> --redirects HTTP requests temporarily without having to contact the origin server. Temporary redirects notify the browser of the URL change for the current request only (by returning an HTTP status code 307).</p>
+ <p><b>Note:</b> use the <code>regex_</code> prefix to indicate that the line has a regular expression.</p></td>
</tr>
<tr>
<td><p><i><code> target</code> </i></p></td>
- <td><p>Enter the origin or <em> from</em> URL. You can enter up to four components:</p>
+ <td><p>Enter the origin ("from") URL. You can enter up to four components:</p>
<p><code> scheme</code> <code> ://<em> host</em> : <em>port</em> / <em> path_prefix</em> </code></p>
<p>where <code> scheme</code> is <code>http</code>.</p></td>
</tr>
<tr>
<td><p><i><code> replacement</code> </i></p></td>
- <td><p>Enter the destination or <em> to</em> URL. You can enter up to four components:</p>
+ <td><p>Enter the destination ("to") <em></em> URL. You can enter up to four components:</p>
<p><Code><em>scheme://host:port/path_prefix</em></code></p>
<p>where <code><em> scheme</em></code> can be <code>http</code> or <code>https</code>.</p></td>
</tr>
@@ -2698,9 +2699,21 @@
<code>redirect http://www.company.com http://www.company2.com </code></p>
<p>The following rule <em>temporarily</em> redirects all HTTP requests for <code>www.company1.com</code> to <code>www.company2.com</code>: <br />
<code>redirect_temporary http://www.company1.com http://www.company2.com </code></p>
+
+
+ <h4>
+ <a name="regex_support">Regular Expression Support</a><a class="moz-txt-link-freetext" href="http://new.$1.z.com"></a></h4>
+<p>Regular expressions can be specified in remapping rules, with the limitations below:</p><ul><li>Only the <code>host</code> field can contain regexes; the <code>scheme</code>, <code>port</code>, and other fields cannot. For path manipulation via regexes, use the <code>regex_remap</code> plugin. </li>
+ <li>The number of capturing subpatterns is limited to 9. This means that <code>$0</code> thru <code>$9</code> can be used as subtraction placeholders (<code>$0</code> will be the entire input string).</li>
+ <li>The number of substitutions in the expansion string is limited to 10.</li>
+ </ul>
+ <h4>
+ Examples</h4>
+ <p><code>regex_map http://x ([0-9]+).z.com http://real-x$1.z.com</code><br>
+ <code>regex_redirect http://old.(.*).z.com http://new.$1.z.com</code></p>
<h2>
- <a name="132448">splitdns.config</a></h2>
- <p>The <code>splitdns.config</code> file enables you to specify the DNS server that Traffic Server should use for resolving hosts under specific conditions. For more information, refer to <a href="secure.htm"><em>Configuring DNS Server Selection (Split DNS)</em></a>. </p>
+ <a name="132448">splitdns.config</a></h2>
+ <p>The <code>splitdns.config</code> file enables you to specify the DNS server that Traffic Server should use for resolving hosts under specific conditions. For more information, refer to <a href="secure.htm">Configuring DNS Server Selection (Split DNS)</a>. </p>
<p>To specify a DNS server, you must supply the following information in each active line within the file: </p>
<ul>
<li>A primary destination specifier in the form of a destination domain, a destination host, or a URL regular expression</li>