WNDR3700 weird routing problem

[vasileiosg]

Hello community,

I live in The Netherlands and my ISP is Ziggo. The ISP router is Cisco EPC3925 in bridge mode towards the Netgear. The problem is that even though I have a Qnap as the DMZ host, from the outside all ports seem to be closed. I have contacted the ISP but they say that all ports are open from their side.

Do you have any ideas what could it be wrong or how to troubleshoot it?

In brief, this is the setup: Internet <--> Cisco <--> Netgear <--> QNAP

[TheEther]

Change the DMZ to a PC and run Wireshark.  Confirm whether you see any traffic coming from the Internet.

If not, then remove the Netgear and put the PC in its place.  Repeat the capture with Wireshark.

The idea is to determine where the traffic is being blocked.  Between these two tests, you should be able to isolate it to either the Cisco or Netgear. 

[Retired_Member]

That router is HOSED regarding port forwarding using UPNP. Manually forward the ports. I'm speaking from experiance, go ahead search back to 2009 give or take a year.