Port forwarding iptables, qemu, linux+windows, firewall?

Question

linux

Hello everyone, tell me how to do it:
There is Linux (Centos 6.7), on it is a Windows Server 2012R2 virtual machine (qemu, libvirt), On a virtual machine, a cloud service for electronic devices.
So I forwarded 80, 3389, 21, ports
For the service there is a desktop CMS, and so it connects to ports 6601-6612.
I forward the same way to iptables^
iptables -t nat -A PREROUTING -dst IP SERVER -p tcp -dport 6601:6612 -j DNAT -to-destination 192.168.122.253
iptables -I FORWARD 2 -i eth0 -o virbr0 -d 192.168.122.253 -p tcp -m tcp --dport 6601:6612 -j ACCEPT
eth0 external, virbr0 virtual machine
face

Answer 1

Judging by
Packets go to the virtual machine.
Check with wireshart / tcpdump on the virtual machine itself whether they reach.
And you still have a lot of the same rules.