diff --git a/pve-network.adoc b/pve-network.adoc
index a33b90c..af3489e 100644
--- a/pve-network.adoc
+++ b/pve-network.adoc
@@ -12,6 +12,11 @@ complete format description. All {pve} tools try hard to keep direct
 user modifications, but using the GUI is still preferable, because it
 protects you from errors.
 
+WARNING: It's discourage to use the Debian traditional tools `ifup` and `ifdown`
+if unsure, as they have some pitfalls like interupting all guest traffic on
+`ifdown vmbrX` but not reconnecting those guest again when doing `ifup` on the
+same bridge later.
+
 Apply Network Changes
 ~~~~~~~~~~~~~~~~~~~~~