<div dir="ltr"><div class="markdown-here-wrapper" style=""><p style="margin:0px 0px 1.2em!important">Greetings,<br>I’ve been trying to debug why systemd-resolve is not able to perform <code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-radius:3px;display:inline">nslookup <a href="http://static-exp1.licdn.com">static-exp1.licdn.com</a></code>.<br>Altering <code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-radius:3px;display:inline">/etc/resolv.conf</code> to point directly to the DNS server (or my router in this case) solves the problem, which seems to suggest the problem is isolated to systemd-resolve.<br>The problem is identical on both my laptops which are running 2 different O.S. (Kubuntu 18.04 and Fedora 33).<br>The entire DNS configuration is provided by the router acting as DHCP server.</p>
<p style="margin:0px 0px 1.2em!important">The system I’m performing my tests is Kubuntu, where the systemd version is:</p>
<pre style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;font-size:1em;line-height:1.2em;margin:1.2em 0px"><code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-radius:3px;display:inline;white-space:pre;overflow:auto;border-radius:3px;border:1px solid rgb(204,204,204);padding:0.5em 0.7em;display:block!important">systemd --version
systemd 237
+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD -IDN2 +IDN -PCRE2 default-hierarchy=hybrid
</code></pre><p style="margin:0px 0px 1.2em!important"><code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-radius:3px;display:inline">SYSTEMD_LOG_LEVEL</code> is set to <code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-radius:3px;display:inline">debug</code>.<br>Is there any other useful tool I can use to debug this further?<br>The problematic domain is <code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-radius:3px;display:inline"><a href="http://static-exp1.licdn.com">static-exp1.licdn.com</a></code> which is the CDN for LinkedIn. I have no idea why <em>this</em> specific domain is affected.</p>
<p style="margin:0px 0px 1.2em!important">Attached the output of <code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-radius:3px;display:inline">journalctl -u systemd-resolved -f</code>, located at this URL: <a href="https://gist.github.com/Fire-Dragon-DoL/8369b07dc27f57f7f05ffa25fd1d6962">https://gist.github.com/Fire-Dragon-DoL/8369b07dc27f57f7f05ffa25fd1d6962</a><br>The output is obtained by running <code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-radius:3px;display:inline">nslookup <a href="http://static-exp1.licdn.com">static-exp1.licdn.com</a></code> after <code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-radius:3px;display:inline">systemd-resolve --flush-caches</code>.</p>
<p style="margin:0px 0px 1.2em!important">Any help is greatly appreciated.<br>My temporary fix is to alter <code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-radius:3px;display:inline">/etc/resolv.conf</code> to sidestep systemd-resolve. I’d like to avoid this approach since it removes local caching</p>
<p style="margin:0px 0px 1.2em!important">—<br>Francesco Belladonna</p>
<div title="MDH:R3JlZXRpbmdzLDxkaXY+SSd2ZSBiZWVuIHRyeWluZyB0byBkZWJ1ZyB3aHkgc3lzdGVtZC1yZXNv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" style="height:0;width:0;max-height:0;max-width:0;overflow:hidden;font-size:0em;padding:0;margin:0"></div></div></div>