Hide port 81 from outside

Hi,

Under a server with varnish on port 80 and nginx running on port 81, running on ispconfig... What is the best way to hide all pages from port 81? What is the best way to hide port 81 to users? with a nginx config or rewrite? with iptables? Please let me know the best way to do it.

Very thanks.

Administración de servidores Linux

 

You can use shimmer, refer link for more info.