diff --git a/README.md b/README.md
index 28d619e8..c1a8e346 100644
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+++ b/README.md
@@ -85,6 +85,8 @@ On this way the other vpns got the new internal routing in ```bird``` and ```bir
 
 ## Babel
 
+if installed nat64 maybe extends port pool by reconfigure local range `sysctl net.ipv4.ip_local_port_range`
+
 ### Babel Gateway
 A babel gateway is a maschine which allow to exit ipv6 default route and recieve the client and nodes subnet