@Liuck1975 

Check your server IP and gateway settings, make sure it is using the new router as the gateway.

Go to What's my IP and check if it shows the same IP as your ER7206 WAN IP.

  @Somnus Thank you for the answer. Yes my server use the right ip of the router. I checked twice to be sure.

  @KJK 

"At the moment, even if I put my server's private ip in the DMZ,"

What exactly does that mean?

It means that first of all I tried through port forwarding to publish my services on the Internet. This test failed, the server is not reachable via public ip. I then tried using DMZ Zone for my server but even then I cannot reach my device. My ISP's router is in passive mode, all traffic is forwarded directly to the ER7206.

Thank you for answering!!! :)

KJK wrote

  @Liuck1975 

 

Is your ISP one of those that use Carrier-grade NAT by any chance? 

  @KJK 

No, the same configuration on a TP-Link Archer MR600 works, the wan port connected to the ISP Router with fixed public IP, Virtual Server active to internal ip address, the router forward the wan traffic to the correct device. I do the same step, also management interface has the same family look. On ER7206 it fails and on Archer MR600 works.

Best regards!!!