Two NAT in one Network: which way we should go with ?

At first time, I was trying to install another Wireless router to existing ADSL Router, I faced with many problem such as Forwarding DVR Port, FTP Data connection port, FTP, … After google, someone advised me to necessaries ports from ADSL router to Wireless Router (Cisco M10)  one by one. At this point, as my experience it’s rather hard to configure, especially FTP Data connection port.

After a while, I’ve decided to reconfigure my network infrastructure again by disabling NAT and DHCP function on the first ADSL Router, it’s mean use it as bridge connection or ADSL only, no router function enable. Because of forwarding from one NAT to another NAT might drain network performance, so I’ve gone straightforward with this scenario. So what’s the problem here, It’s very hard to access the ADSL router web interface to check internet connection link or something else with ISP.

So just today, I decided to configure ADSL Router to act as normal with DHCP, NAT and firewall enabled and connect it to Cisco M10 wireless router. I’m going back to two NAT in one network again. But I found the best solution to make all things work is : I don’t need to configure the Virtual Server to forward specific port to the second router (Cisco M10) one by one, I just configured the DMZ server to Cisco M10 wireless router’s IP. So it’s done!