sahinakkaya.dev/2022/02/26/ssh-into-machine-that-is-behind-private-network.html
2022-06-22 14:47:50 +00:00

660 lines
20 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!doctype html>
<!--
Minimal Mistakes Jekyll Theme 4.24.0 by Michael Rose
Copyright 2013-2020 Michael Rose - mademistakes.com | @mmistakes
Free for personal and commercial use under the MIT license
https://github.com/mmistakes/minimal-mistakes/blob/master/LICENSE
-->
<html lang="en" class="no-js">
<head>
<meta charset="utf-8">
<!-- begin _includes/seo.html --><title>SSH into Machine That Is Behind a Private Network - Şahin Akkayas Personal Page</title>
<meta name="description" content="Story I believe there is always a “tech support person” in every home. Everyone knows that when there is a problem with any electronic device, they should ask this person. I am the tech support in our house. Today, I had to fix a problem in our desktop. Since I was not at home, I had to fix the problem remotely.">
<meta name="author" content="Şahin Akkaya">
<meta property="article:author" content="Şahin Akkaya">
<meta property="og:type" content="article">
<meta property="og:locale" content="en_US">
<meta property="og:site_name" content="Şahin Akkaya's Personal Page">
<meta property="og:title" content="SSH into Machine That Is Behind a Private Network">
<meta property="og:url" content="https://sahinakkaya.dev/2022/02/26/ssh-into-machine-that-is-behind-private-network.html">
<meta property="og:description" content="Story I believe there is always a “tech support person” in every home. Everyone knows that when there is a problem with any electronic device, they should ask this person. I am the tech support in our house. Today, I had to fix a problem in our desktop. Since I was not at home, I had to fix the problem remotely.">
<meta property="article:published_time" content="2022-02-26T21:40:00+00:00">
<link rel="canonical" href="https://sahinakkaya.dev/2022/02/26/ssh-into-machine-that-is-behind-private-network.html">
<script type="application/ld+json">
{
"@context": "https://schema.org",
"@type": "Person",
"name": null,
"url": "https://sahinakkaya.dev/"
}
</script>
<!-- end _includes/seo.html -->
<link href="/feed.xml" type="application/atom+xml" rel="alternate" title="Şahin Akkaya's Personal Page Feed">
<!-- https://t.co/dKP3o1e -->
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<script>
document.documentElement.className = document.documentElement.className.replace(/\bno-js\b/g, '') + ' js ';
</script>
<!-- For all browsers -->
<link rel="stylesheet" href="/assets/css/main.css">
<link rel="preload" href="https://cdn.jsdelivr.net/npm/@fortawesome/fontawesome-free@5/css/all.min.css" as="style" onload="this.onload=null;this.rel='stylesheet'">
<noscript><link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@fortawesome/fontawesome-free@5/css/all.min.css"></noscript>
<!-- start custom head snippets -->
<!-- insert favicons. use https://realfavicongenerator.net/ -->
<!-- end custom head snippets -->
</head>
<body class="layout--single">
<nav class="skip-links">
<ul>
<li><a href="#site-nav" class="screen-reader-shortcut">Skip to primary navigation</a></li>
<li><a href="#main" class="screen-reader-shortcut">Skip to content</a></li>
<li><a href="#footer" class="screen-reader-shortcut">Skip to footer</a></li>
</ul>
</nav>
<!--[if lt IE 9]>
<div class="notice--danger align-center" style="margin: 0;">You are using an <strong>outdated</strong> browser. Please <a href="https://browsehappy.com/">upgrade your browser</a> to improve your experience.</div>
<![endif]-->
<div class="masthead">
<div class="masthead__inner-wrap">
<div class="masthead__menu">
<nav id="site-nav" class="greedy-nav">
<a class="site-title" href="/">
/home/sahin/
</a>
<ul class="visible-links"><li class="masthead__menu-item">
<a href="/">Home</a>
</li><li class="masthead__menu-item">
<a href="/about/">About</a>
</li><li class="masthead__menu-item">
<a href="/contact/">Contact</a>
</li></ul>
<button class="search__toggle" type="button">
<span class="visually-hidden">Toggle search</span>
<i class="fas fa-search"></i>
</button>
<button class="greedy-nav__toggle hidden" type="button">
<span class="visually-hidden">Toggle menu</span>
<div class="navicon"></div>
</button>
<ul class="hidden-links hidden"></ul>
</nav>
</div>
</div>
</div>
<div class="initial-content">
<div id="main" role="main">
<div class="sidebar sticky">
<div itemscope itemtype="https://schema.org/Person">
<div class="author__avatar">
<img src="/assets/images/logo.jpg" alt="Şahin Akkaya" itemprop="image">
</div>
<div class="author__content">
<h3 class="author__name" itemprop="name">Şahin Akkaya</h3>
<div class="author__bio" itemprop="description">
<p>A perfectionist who likes to tinker everything until it is just right.</p>
</div>
</div>
<div class="author__urls-wrapper">
<button class="btn btn--inverse">Follow</button>
<ul class="author__urls social-icons">
<li itemprop="homeLocation" itemscope itemtype="https://schema.org/Place">
<i class="fas fa-fw fa-map-marker-alt" aria-hidden="true"></i> <span itemprop="name">Istanbul, Turkey</span>
</li>
<li><a href="https://github.com/Asocia" rel="nofollow noopener noreferrer"><i class="fab fa-fw fa-github" aria-hidden="true"></i><span class="label">Asocia</span></a></li>
<li><a href="https://stackoverflow.com/users/9608759" rel="nofollow noopener noreferrer"><i class="fab fa-fw fa-stack-overflow" aria-hidden="true"></i><span class="label">Asocia</span></a></li>
<li><a href="https://twitter.com/sahinakkayadev" rel="nofollow noopener noreferrer"><i class="fab fa-fw fa-twitter-square" aria-hidden="true"></i><span class="label">@sahinakkayadev</span></a></li>
<li><a href="mailto:sahin@sahinakkaya.dev" rel="nofollow noopener noreferrer"><i class="fas fa-fw fa-envelope" aria-hidden="true"></i><span class="label">sahin@sahinakkaya.dev</span></a></li>
<li><a href="/assets/docs/resume.pdf" rel="nofollow noopener noreferrer"><i class="fas fa-fw fa-id-card" aria-hidden="true"></i><span class="label">Resume</span></a></li>
<!--
<li>
<a href="http://link-to-whatever-social-network.com/user/" itemprop="sameAs" rel="nofollow noopener noreferrer">
<i class="fas fa-fw" aria-hidden="true"></i> Custom Social Profile Link
</a>
</li>
-->
</ul>
</div>
</div>
</div>
<article class="page" itemscope itemtype="https://schema.org/CreativeWork">
<meta itemprop="headline" content="SSH into Machine That Is Behind a Private Network">
<meta itemprop="description" content="StoryI believe there is always a “tech support person” in every home. Everyone knows that when there is a problem with any electronic device, they should ask this person. I am the tech support in our house. Today, I had to fix a problem in our desktop. Since I was not at home, I had to fix the problem remotely.">
<meta itemprop="datePublished" content="2022-02-26T21:40:00+00:00">
<div class="page__inner-wrap">
<header>
<h1 id="page-title" class="page__title" itemprop="headline">SSH into Machine That Is Behind a Private Network
</h1>
<p class="page__meta">
<span class="page__meta-date">
<i class="far fa-calendar-alt" aria-hidden="true"></i>
<time datetime="2022-02-26T21:40:00+00:00">February 26, 2022</time>
</span>
<span class="page__meta-sep"></span>
<span class="page__meta-readtime">
<i class="far fa-clock" aria-hidden="true"></i>
2 minute read
</span>
</p>
</header>
<section class="page__content" itemprop="text">
<h2 id="story">Story</h2>
<p>I believe there is always a “tech support person” in every home. Everyone knows that when there is a problem with any electronic device, they should ask this person. I am the tech support in our house. Today, I had to fix a problem in our desktop. Since I was not at home, I had to fix the problem remotely.</p>
<h2 id="possible-solutions">Possible solutions</h2>
<ul>
<li>
<p>Just tell the non-tech people at home to configure the router to forward ssh traffic to desktop, right? Well, this is not an option for me, not because people are non-tech, but there is no router! The desktop is connected to internet via hotspot from mobile phone. There is no root access in the phone and even if there was, it is a really big pain to forward the packets manually. Trust me. Been there, done that!</p>
</li>
<li>
<p>There are tools like <a href="https://www.ngrok.com">ngrok</a>, <a href="localtunnel.me">localtunnel</a> which exposes your localhost to the internet and gives you a URL to access it but I did not want to use them.</p>
<ul>
<li>I did not want to use <code class="language-plaintext highlighter-rouge">ngrok</code> because it is not open source and it might have security issues. They are also charging you.</li>
<li><code class="language-plaintext highlighter-rouge">localtunnel</code> seemed perfect. The code of both client and server is open. That is great news! But it did not last long because it is just forwarding http/https traffic :(</li>
</ul>
</li>
</ul>
<h2 id="solution">Solution</h2>
<p>I was thinking of extending the functionality of <code class="language-plaintext highlighter-rouge">localtunnel</code>, but I learned a very simple way. You dont need any external program to overcome this issue. The good old <code class="language-plaintext highlighter-rouge">ssh</code> can do that! All you need is another machine (a remote server) that both computers can access via ssh.</p>
<div class="language-bash highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="c"># local machine (my home computer)</span>
ssh <span class="nt">-R</span> 7777:localhost:22 remote-user@remote.host
</code></pre></div></div>
<p>This command forwards all the incoming connections to port 7777 of remote machine to port 22 of our current machine. In order for this to work, you need to make sure <code class="language-plaintext highlighter-rouge">GatewayPorts</code> is set to <code class="language-plaintext highlighter-rouge">yes</code> in the remote server ssh configuration. It also assumes our current machine accepts ssh connections via port 22.</p>
<hr />
<p>Now, go to any machine and connect to the remote server first. When we are connected, we will create another ssh connection to port 7777 to connect our home computer.</p>
<div class="language-bash highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="c"># another local machine (my laptop)</span>
ssh remote-user@remote.host
<span class="c"># connected remote</span>
ssh <span class="nt">-p</span> 7777 homeuser@localhost
<span class="c"># we are now connected to home computer</span>
</code></pre></div></div>
<p>The last two command can also combined so that we directly hop into the home computer.</p>
<div class="language-bash highlighter-rouge"><div class="highlight"><pre class="highlight"><code>ssh <span class="nt">-t</span> remote-user@remote.host ssh <span class="nt">-p</span> 7777 homeuser@localhost
</code></pre></div></div>
<h3 id="result">Result</h3>
<p>As a result, it only took us 2 simple ssh commands to do this. This is just unbelievable! Now, I need to find a way to make non-tech people at home run this command when there is a problem. Too bad Linux cant help me there :D</p>
</section>
<footer class="page__meta">
<p class="page__date"><strong><i class="fas fa-fw fa-calendar-alt" aria-hidden="true"></i> Updated:</strong> <time datetime="2022-02-26T21:40:00+00:00">February 26, 2022</time></p>
</footer>
<section class="page__share">
<a href="https://twitter.com/intent/tweet?text=SSH+into+Machine+That+Is+Behind+a+Private+Network%20https%3A%2F%2Fsahinakkaya.dev%2F2022%2F02%2F26%2Fssh-into-machine-that-is-behind-private-network.html" class="btn btn--twitter" onclick="window.open(this.href, 'window', 'left=20,top=20,width=500,height=500,toolbar=1,resizable=0'); return false;" title="Share on Twitter"><i class="fab fa-fw fa-twitter" aria-hidden="true"></i><span> Twitter</span></a>
<a href="https://www.facebook.com/sharer/sharer.php?u=https%3A%2F%2Fsahinakkaya.dev%2F2022%2F02%2F26%2Fssh-into-machine-that-is-behind-private-network.html" class="btn btn--facebook" onclick="window.open(this.href, 'window', 'left=20,top=20,width=500,height=500,toolbar=1,resizable=0'); return false;" title="Share on Facebook"><i class="fab fa-fw fa-facebook" aria-hidden="true"></i><span> Facebook</span></a>
<a href="https://www.linkedin.com/shareArticle?mini=true&url=https%3A%2F%2Fsahinakkaya.dev%2F2022%2F02%2F26%2Fssh-into-machine-that-is-behind-private-network.html" class="btn btn--linkedin" onclick="window.open(this.href, 'window', 'left=20,top=20,width=500,height=500,toolbar=1,resizable=0'); return false;" title="Share on LinkedIn"><i class="fab fa-fw fa-linkedin" aria-hidden="true"></i><span> LinkedIn</span></a>
</section>
<nav class="pagination">
<a href="/2022/01/21/ffmpeg-to-rescue.html" class="pagination--pager" title="Using ffmpeg for Simple Video Editing
">Previous</a>
<a href="/2022/02/27/creating-a-useless-user.html" class="pagination--pager" title="Creating a Useless User
">Next</a>
</nav>
</div>
</article>
<div class="page__related">
<h4 class="page__related-title">You May Also Enjoy</h4>
<div class="grid__wrapper">
<div class="grid__item">
<article class="archive__item" itemscope itemtype="https://schema.org/CreativeWork">
<h2 class="archive__item-title no_toc" itemprop="headline">
<a href="/2022/06/22/rant-on-peoples-reaction-to-copilot.html" rel="permalink">Rant: Stop whatever you are doing and learn how licenses work
</a>
</h2>
<p class="page__meta">
<span class="page__meta-date">
<i class="far fa-fw fa-calendar-alt" aria-hidden="true"></i>
<time datetime="2022-06-22T07:46:00+00:00">June 22, 2022</time>
</span>
<span class="page__meta-sep"></span>
<span class="page__meta-readtime">
<i class="far fa-fw fa-clock" aria-hidden="true"></i>
2 minute read
</span>
</p>
<p class="archive__item-excerpt" itemprop="description">Recently, Github announced
that they are making Github Copilot available for everyone. Previously, it was in Beta and you could get it through the waiting l...</p>
</article>
</div>
<div class="grid__item">
<article class="archive__item" itemscope itemtype="https://schema.org/CreativeWork">
<h2 class="archive__item-title no_toc" itemprop="headline">
<a href="/2022/04/08/confession-time.html" rel="permalink">Confession Time
</a>
</h2>
<p class="page__meta">
<span class="page__meta-date">
<i class="far fa-fw fa-calendar-alt" aria-hidden="true"></i>
<time datetime="2022-04-08T15:46:00+00:00">April 8, 2022</time>
</span>
<span class="page__meta-sep"></span>
<span class="page__meta-readtime">
<i class="far fa-fw fa-clock" aria-hidden="true"></i>
2 minute read
</span>
</p>
<p class="archive__item-excerpt" itemprop="description">A failure story
Last week, I received an email from Lets Encrypt reminding me to renew my certificates. I forgot to renew it and the certificate expired. No...</p>
</article>
</div>
<div class="grid__item">
<article class="archive__item" itemscope itemtype="https://schema.org/CreativeWork">
<h2 class="archive__item-title no_toc" itemprop="headline">
<a href="/2022/03/03/never-get-trapped-in-grub-rescue-again.html" rel="permalink">Never Get Trapped in Grub Rescue Again!
</a>
</h2>
<p class="page__meta">
<span class="page__meta-date">
<i class="far fa-fw fa-calendar-alt" aria-hidden="true"></i>
<time datetime="2022-03-03T00:46:00+00:00">March 3, 2022</time>
</span>
<span class="page__meta-sep"></span>
<span class="page__meta-readtime">
<i class="far fa-fw fa-clock" aria-hidden="true"></i>
4 minute read
</span>
</p>
<p class="archive__item-excerpt" itemprop="description">Anytime I install a new system on my machine, I pray God for nothing bad happens. But it usually happens. When I reboot, I find myself in the “Grub rescue” m...</p>
</article>
</div>
<div class="grid__item">
<article class="archive__item" itemscope itemtype="https://schema.org/CreativeWork">
<h2 class="archive__item-title no_toc" itemprop="headline">
<a href="/2022/02/27/creating-a-useless-user.html" rel="permalink">Creating a <em>Useless</em> User
</a>
</h2>
<p class="page__meta">
<span class="page__meta-date">
<i class="far fa-fw fa-calendar-alt" aria-hidden="true"></i>
<time datetime="2022-02-27T13:40:00+00:00">February 27, 2022</time>
</span>
<span class="page__meta-sep"></span>
<span class="page__meta-readtime">
<i class="far fa-fw fa-clock" aria-hidden="true"></i>
1 minute read
</span>
</p>
<p class="archive__item-excerpt" itemprop="description">Story
In my previous post, I explained how to do port forwarding to access some machine behind private network. I will use this method to fix some issues in ...</p>
</article>
</div>
</div>
</div>
</div>
</div>
<div class="search-content">
<div class="search-content__inner-wrap"><form class="search-content__form" onkeydown="return event.key != 'Enter';">
<label class="sr-only" for="search">
Enter your search term...
</label>
<input type="search" id="search" class="search-input" tabindex="-1" placeholder="Enter your search term..." />
</form>
<div id="results" class="results"></div></div>
</div>
<div id="footer" class="page__footer">
<footer>
<!-- start custom footer snippets -->
<!-- end custom footer snippets -->
<div class="page__footer-follow">
<ul class="social-icons">
<li><a href="/feed.xml"><i class="fas fa-fw fa-rss-square" aria-hidden="true"></i> Feed</a></li>
</ul>
</div>
<div class="page__footer-copyright">&copy; 2022 Şahin Akkaya's Personal Page. Powered by <a href="https://jekyllrb.com" rel="nofollow">Jekyll</a> &amp; <a href="https://mademistakes.com/work/minimal-mistakes-jekyll-theme/" rel="nofollow">Minimal Mistakes</a>.</div>
<div class="page__footer-copyright">
Check out the <a href="https://github.com/Asocia/sahinakkayadotdev">code</a> of this site.
</div>
</footer>
</div>
<script src="/assets/js/main.min.js"></script>
<script src="/assets/js/lunr/lunr.min.js"></script>
<script src="/assets/js/lunr/lunr-store.js"></script>
<script src="/assets/js/lunr/lunr-en.js"></script>
</body>
</html>