CentOS - Jan 2017 - Centos 7 force reverse dns lookup for none registered addr

I have an application running on a home network. the client is windows and
the server is Centos 7.  ?I can access the application from a browser, but
when I try a HTTP POST  from another Centos 7 box (CLI) I get 54 ECONNRESET
Connection reset by peer RECV. after reviewing TCPDUMP i see that Centos
drops the connection after trying to do a reverse DNS lookup. The problem
is that I am not using DNS but direct IP addresses.
How can I force Centos not to do a reverse DNS lookup?

Best,
ITschak

> On Jan 10, 2017, at 4:17 PM, Itschak Mugzach <imugzach at gmail.com>
wrote:
> 
> after reviewing TCPDUMP
Did you `tcpdump` with the -nn option? If not than tcpdump was probably doing
the reverse DNS lookup.