https://www.devkuma.com/en/tags/centos/ https://www.devkuma.com/en/tags/centos/logo/180x180.jpg https://www.devkuma.com/en/tags/centos/ Recent content in CentOS on devkuma Hugo -- gohugo.io en kc@example.com (kc kim) kc@example.com (kc kim) The devkuma https://www.devkuma.com/en/docs/linux/cent-os/firewall-cmd/ Fri, 04 Nov 2022 08:46:00 +0900 kc@example.com (kc kim) https://www.devkuma.com/en/docs/linux/cent-os/firewall-cmd/ <p>Starting with CentOS 7, firewall-related work should use <code>firewall-cmd</code> instead of iptables-related commands.</p> <h2 id="opening-a-port">Opening a Port</h2> <p>Open a port as follows.</p> <div class="highlight"><pre tabindex="0" style="background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>firewall-cmd --zone<span style="color:#ce5c00;font-weight:bold">=</span>public --permanent --add-port<span style="color:#ce5c00;font-weight:bold">={</span>port number<span style="color:#ce5c00;font-weight:bold">}</span>/tcp </span></span></code></pre></div><p>Apply the setting.</p> <div class="highlight"><pre tabindex="0" style="background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>firewall-cmd --reload </span></span></code></pre></div><p>Actual example:</p> <div class="highlight"><pre tabindex="0" style="background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span><span style="color:#ce5c00;font-weight:bold">[</span>root@localhost ~<span style="color:#ce5c00;font-weight:bold">]</span><span style="color:#8f5902;font-style:italic"># firewall-cmd --zone=public --permanent --add-port=9090/tcp</span> </span></span><span style="display:flex;"><span>success </span></span><span style="display:flex;"><span><span style="color:#ce5c00;font-weight:bold">[</span>root@localhost ~<span style="color:#ce5c00;font-weight:bold">]</span><span style="color:#8f5902;font-style:italic"># firewall-cmd --reload</span> </span></span><span style="display:flex;"><span>success </span></span></code></pre></div><h2 id="checking-open-ports">Checking Open Ports</h2> <p>Use the following command to check open ports.</p> <div class="highlight"><pre tabindex="0" style="background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>firewall-cmd --zone<span style="color:#ce5c00;font-weight:bold">=</span>public --list-all </span></span></code></pre></div><div class="highlight"><pre tabindex="0" style="background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span><span style="color:#ce5c00;font-weight:bold">[</span>root@localhost ~<span style="color:#ce5c00;font-weight:bold">]</span><span style="color:#8f5902;font-style:italic"># firewall-cmd --zone=public --list-all</span> </span></span><span style="display:flex;"><span>public <span style="color:#ce5c00;font-weight:bold">(</span>active<span style="color:#ce5c00;font-weight:bold">)</span> </span></span><span style="display:flex;"><span> target: default </span></span><span style="display:flex;"><span> icmp-block-inversion: no </span></span><span style="display:flex;"><span> interfaces: eth0 </span></span><span style="display:flex;"><span> sources: </span></span><span style="display:flex;"><span> services: dhcpv6-client ssh </span></span><span style="display:flex;"><span> ports: 9090/tcp </span></span></code></pre></div><p>You can confirm that port <code>9090</code>, opened above, is listed.</p> Linux OS CentOS