docs: Default network unreachable

README.md

@@ -49,4 +49,21 @@ This should not happen, the image has a dedicated Polkit policy for this. If you
 
 ### Cannot connect to a remote libvirt daemon over SSH
 
-Please, refer to [this](https://github.com/89luca89/distrobox/blob/main/docs/posts/run_libvirt_in_distrobox.md) from the Distrobox documentation.
+Please, refer to [this](https://github.com/89luca89/distrobox/blob/main/docs/posts/run_libvirt_in_distrobox.md) from the Distrobox documentation.
+
+### Default network unreachable
+
+If the default network is unreachable, try to start it manually:
+
+```bash
+sudo virsh net-start default
+virsh net-autostart default
+```
+
+if the above command fails due to missing network, try loading it from the XML:
+
+```bash
+sudo virsh net-define /usr/share/libvirt/networks/default.xml
+sudo virsh net-start default
+virsh net-autostart default
+```