Update k8s-best-practices-multus-macvlan.adoc

Author: mwlinca

modules/k8s-best-practices-multus-macvlan.adoc

@@ -13,6 +13,12 @@ Different names will be assigned to different Network Attachment Definitions tha
 
 For SR-IOV based SriovNetworkNodePolicy definitions, the MTU setting is omitted because it can cause conflicts with applications which set their own MTU value. It is required therefore that the application always manage its own MTU value for SR-IOV
 
+.Workload requirement
+[IMPORTANT]
+====
+Applications must not use an MTU size greater than 8500 bytes
+====
+
 .Workload requirement
 [IMPORTANT]
 ====