Installing-using-Docker-(recommended!).md

@@ -5,6 +5,7 @@
 Firstly, you need a system running docker. For debian-based systems, this is simple:
 
 `apt-get install docker.io`
+`apt-get install conntrack`
 
 A change needs to be made to the docker config for openbridge to work correctly:
 
@@ -156,4 +157,10 @@ Hopefully this will run fine. If you have made any mistakes you may have to stop
 
 `docker container restart freedmr`
 
+## After FreeDMR is updated or restarted 
+
+`conntrack -F`
+
+This flushes the connection tracking table for NAT. Without this, you might not see traffic for a while. 
+