Add Docs / Pinging / Network Routers

templates/docs/network_routers.html-fragment

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+<h1>Network Routers</h1>
+<p>Certain network router operating systems can be configured to send regular HTTP(S)
+requests to SITE_NAME directly from the router. This is a handy way to monitor them: when
+the router loses its WAN connection, it will not be able to ping SITE_NAME, and SITE_NAME
+will notify you about the outage.</p>
+<h2>DD-WRT</h2>
+<p><a href="https://dd-wrt.com/">DD-WRT</a> is a Linux-based firmware for routers that runs on wide
+variety of router models. DD-WRT ships with a cron daemon and wget utility. You can
+enable the cron daemon and edit crontab in DD-WRT control panel,
+<strong>Administration › Management › Cron</strong>.</p>
+<p>The crontab syntax on DD-WRT is:</p>
+<div class="highlight"><pre><span></span><code><span class="p">[</span><span class="n">cron</span><span class="w"> </span><span class="n">expression</span><span class="p">]</span><span class="w"> </span><span class="p">[</span><span class="n">username</span><span class="p">]</span><span class="w"> </span><span class="p">[</span><span class="n">command</span><span class="p">]</span>
+</code></pre></div>
+
+<p>Example for sending a ping every minute:</p>
+<div class="highlight"><pre><span></span><code><span class="k">*</span> * <span class="gs">* *</span> * root wget PING_URL
+</code></pre></div>
+
+<p>Screenshot:</p>
+<p><img alt="DD-WRT control panel" src="IMG_URL/ddwrt.png" /></p>
+<h2>MikroTik RouterOS</h2>
+<p><a href="https://mikrotik.com/software">MikroTik RouterOS</a> is a router operating system used
+primarily on MikroTik network hardware. Among its many features is scripting support
+and a scheduler.</p>
+<p>First, create a script in WebFig, <strong>System › Scripts › Add New</strong>. Use the following
+parameters:</p>
+<ul>
+<li>Name: <code>ping</code> (example, you can use a different name)</li>
+<li>Policy: <code>read</code>, <code>test</code></li>
+<li>Source: <code>/tool fetch url="/tool fetch url="PING_URL" output=none</code></li>
+</ul>
+<p><img alt="DD-WRT control panel" src="IMG_URL/routeros1.png" /></p>
+<p>Then, create a schedule in WebFig, <strong>System › Scheduler › Add New</strong>. Use parameters:</p>
+<ul>
+<li>Interval: <code>00:01:00</code> (one minute)</li>
+<li>Policy: <code>read</code>, <code>test</code></li>
+<li>On Event: <code>ping</code> (the name of the script from the previous step)</li>
+</ul>
+<p><img alt="DD-WRT control panel" src="IMG_URL/routeros2.png" /></p>
+<p>Notes:</p>
+<ul>
+<li>The <code>output=none</code> parameter tells the system to discard response body. Without
+  this parameter, the system will save response body to a file, which will additionally
+  require the <code>write</code> policy.</li>
+<li>The "tool fetch" utility supports HTTPS URLs but does not verify TLS certificates
+  by default. You can add <code>check-certificate=yes</code> parameter to require a valid TLS
+  certificate. Note that RouterOS ships with no root CA certificates, so you will
+  also need to load these.</li>
+<li><a href="https://wiki.mikrotik.com/wiki/Manual:Tools/Fetch">Here's the full list of options</a>
+  supported by "tool fetch".</li>
+</ul>

templates/docs/network_routers.md

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+# Network Routers
+
+Certain network router operating systems can be configured to send regular HTTP(S)
+requests to SITE_NAME directly from the router. This is a handy way to monitor them: when
+the router loses its WAN connection, it will not be able to ping SITE_NAME, and SITE_NAME
+will notify you about the outage.
+
+## DD-WRT
+
+[DD-WRT](https://dd-wrt.com/) is a Linux-based firmware for routers that runs on wide
+variety of router models. DD-WRT ships with a cron daemon and wget utility. You can
+enable the cron daemon and edit crontab in DD-WRT control panel,
+**Administration › Management › Cron**.
+
+The crontab syntax on DD-WRT is:
+
+    [cron expression] [username] [command]
+
+Example for sending a ping every minute:
+
+    * * * * * root wget PING_URL
+
+Screenshot:
+
+![DD-WRT control panel](IMG_URL/ddwrt.png)
+
+## MikroTik RouterOS
+
+[MikroTik RouterOS](https://mikrotik.com/software) is a router operating system used
+primarily on MikroTik network hardware. Among its many features is scripting support
+and a scheduler.
+
+First, create a script in WebFig, **System › Scripts › Add New**. Use the following
+parameters:
+
+* Name: `ping` (example, you can use a different name)
+* Policy: `read`, `test`
+* Source: `/tool fetch url="/tool fetch url="PING_URL" output=none`
+
+![DD-WRT control panel](IMG_URL/routeros1.png)
+
+Then, create a schedule in WebFig, **System › Scheduler › Add New**. Use parameters:
+
+* Interval: `00:01:00` (one minute)
+* Policy: `read`, `test`
+* On Event: `ping` (the name of the script from the previous step)
+
+![DD-WRT control panel](IMG_URL/routeros2.png)
+
+Notes:
+
+* The `output=none` parameter tells the system to discard response body. Without
+  this parameter, the system will save response body to a file, which will additionally
+  require the `write` policy.
+* The "tool fetch" utility supports HTTPS URLs but does not verify TLS certificates
+  by default. You can add `check-certificate=yes` parameter to require a valid TLS
+  certificate. Note that RouterOS ships with no root CA certificates, so you will
+  also need to load these.
+* [Here's the full list of options](https://wiki.mikrotik.com/wiki/Manual:Tools/Fetch)
+  supported by "tool fetch".
+
+
+

templates/front/docs_single.html

@@ -37,6 +37,7 @@
         {% include "front/docs_nav_item.html" with slug="reliability_tips" title="Reliability tips" %}
         {% include "front/docs_nav_item.html" with slug="bash" title="Shell scripts" %}
         {% include "front/docs_nav_item.html" with slug="arduino" title="Arduino" %}
+        {% include "front/docs_nav_item.html" with slug="network_routers" title="Network Routers" %}
         {% include "front/docs_nav_item.html" with slug="csharp" title="C#" %}
         {% include "front/docs_nav_item.html" with slug="email" title="Email" %}
         {% include "front/docs_nav_item.html" with slug="github_actions" title="GitHub Actions" %}