<div dir="ltr"><div><div style="font-size:small" class="gmail_default">I am having a puzzling issue with my VPN network, which uses Wireguard, and has been working well for months. </div><div style="font-size:small" class="gmail_default">Then a few days ago, things started going wrong.</div><div style="font-size:small" class="gmail_default"><br></div><div style="font-size:small" class="gmail_default">A service (e.g. Home Assistant, Grafana) would load from my phone, but fails to load from my laptop.</div><div style="font-size:small" class="gmail_default">My phone and my laptop are peers in the Wireguard VPN.</div><div style="font-size:small" class="gmail_default"><br></div><div style="font-size:small" class="gmail_default">The issue does not seem to be a firewall issue, because I have not changed that at all, and I do see responses, but no traffic.</div><div style="font-size:small" class="gmail_default"><br></div><div style="font-size:small" class="gmail_default">When I use curl, I get back a response, which is an HTTP redirect:</div><div style="font-size:small" class="gmail_default"><br></div><div style="font-size:small" class="gmail_default"><span style="font-family:monospace"><span style="color:rgb(0,0,0);background-color:rgb(255,255,255)">$ curl <a href="http://s1.example.com:3000">s1.example.com:3000</a>
</span><br><a href="/login">Found</a>. <br></span></div><div style="font-size:small" class="gmail_default"><span style="font-family:monospace"><span style="color:rgb(0,0,0);background-color:rgb(255,255,255)"><br></span></span></div><div style="font-size:small" class="gmail_default"><div style="font-size:small" class="gmail_default">But when I go to that URL, the browser (or curl) hangs there indefinitely.</div><div style="font-size:small" class="gmail_default"><br></div><div style="font-size:small" class="gmail_default"><span style="font-family:monospace"><span style="color:rgb(0,0,0);background-color:rgb(255,255,255)">$ curl </span></span><span style="font-family:monospace"><span style="color:rgb(0,0,0);background-color:rgb(255,255,255)"><a href="http://s1.example.com">s1.example.com</a></span></span><span style="font-family:monospace"><span style="color:rgb(0,0,0);background-color:rgb(255,255,255)">:3000/login # Grafana, Hangs</span><br></span><br></div><div style="font-size:small" class="gmail_default"><span style="font-family:monospace"><span style="color:rgb(0,0,0);background-color:rgb(255,255,255)">$ curl </span></span><span style="font-family:monospace"><span style="color:rgb(0,0,0);background-color:rgb(255,255,255)"><a href="http://s1.example.com">s1.example.com</a></span></span><span style="font-family:monospace"><span style="color:rgb(0,0,0);background-color:rgb(255,255,255)">:8123/ # Home Assistant, Hangs </span></span></div><div style="font-size:small" class="gmail_default"><br></div><div style="font-size:small" class="gmail_default"><div style="font-size:small" class="gmail_default">Again, some requests with errors do send back responses:</div><br></div><div style="font-size:small" class="gmail_default"><span style="font-family:monospace"><span style="color:rgb(0,0,0);background-color:rgb(255,255,255)">$ curl </span></span><span style="font-family:monospace"><span style="color:rgb(0,0,0);background-color:rgb(255,255,255)"><a href="http://s1.example.com">s1.example.com</a></span></span><span style="font-family:monospace"><span style="color:rgb(0,0,0);background-color:rgb(255,255,255)">:8123/foo # Home Assistant, with an invalid URL</span><br></span></div><div style="font-size:small" class="gmail_default"><span style="font-family:monospace">404: Not Found</span></div><br><div style="font-size:small" class="gmail_default">But I do see bytes being queued in netstat on the target machine (3rd column).</div><div style="font-size:small" class="gmail_default"><br></div><div style="font-size:small" class="gmail_default"><span style="font-family:monospace"><span style="color:rgb(0,0,0);background-color:rgb(255,255,255)">tcp 0 5606 <a href="http://10.10.0.4:8123">10.10.0.4:8123</a> <a href="http://10.10.0.2:50322">10.10.0.2:50322</a> ESTABLISHED 4071/python3</span><br></span><br></div><div style="font-size:small" class="gmail_default">Then it goes from ESTABLISHED to CLOSING to CLOSE_WAIT ...etc.</div><div style="font-size:small" class="gmail_default"><br></div><div style="font-size:small" class="gmail_default">I restarted the Wireguard tunnels on both machines, just in case:</div><div style="font-size:small" class="gmail_default"><br></div><div style="font-size:small" class="gmail_default"><span style="font-family:monospace"><span style="color:rgb(0,0,0);background-color:rgb(255,255,255)">$ sudo systemctl status wg-quick@wg0</span><br></span><br></div><div style="font-size:small" class="gmail_default">And it made no difference.</div><div style="font-size:small" class="gmail_default"><br></div><div style="font-size:small" class="gmail_default">This is happening for various services, but only from specific machines, but not others.</div><div style="font-size:small" class="gmail_default"><br></div>How can one go about troubleshooting this pesky problem?</div></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature">Khalid M. Baheyeldin</div></div>