diff --git a/Hadoop-Compatible-File-System.md b/Hadoop-Compatible-File-System.md
index 2684e8b..1b07638 100644
--- a/Hadoop-Compatible-File-System.md
+++ b/Hadoop-Compatible-File-System.md
@@ -182,3 +182,5 @@ This is different from many other HCFS options. If native shared libraries are n
 ## Shaded Fat Jar
 One of the headache with complicated Java systems is the jar runtime dependency problem, which is resolved by Go's build time dependency resolution. For this SeaweedFS hadoop client, the required jars are mostly shaded and packaged as one fat jar, so there are no extra jar files needed.
 
+## Note
+* use `-Djava.net.preferIPv4Stack=true` if possible, see https://github.com/netty/netty/issues/6454