Add some hints how to set the unique ID

site/faq.md

@@ -48,6 +48,9 @@ machine in your cluster to have a unique identity.
 
 For more information see [Peer Names](/site/operational-guide/concepts.md#peer-name).
 
+Depending on your Linux distribution you may need to [set up
+machine-id](https://www.freedesktop.org/software/systemd/man/machine-id.html)
+or [generate a dbus id](https://dbus.freedesktop.org/doc/dbus-uuidgen.1.html).
 
 <a name="duplicate-ip"></a>
 **Q: Why am I seeing the same IP address assigned to two different containers on different hosts?**