Not Able to Port Forward

[jhinkle]

I've moved a TCP Server application behind my R8000.

My Client software attempts to connect using the WAN address associated with my modem.

Port Forwarding is set up to pass any TCP/UDP message to a specific computer (IP address).

It appears the R8000 is not allowing a connection to be made.

I have tried enabling DMZ and disabling NAT filtering.

It acts as if a firewall is preventing communications from coming in.

In an attempt to debug I tried a Client on the same side of the router as the server -- having the client attempt to connect via the WAN address.  I've used wireshark to capture the traffic.

The client issues a TCP connect (SYN) and the WAN returns a RST_ACK -- which I suspect is coming from the R8000 blocking the access.

Any help on resolving this firewall/port forwarding issue I have?

Thanks.

[jhinkle · Accepted solution]

Thanks for reply -- issue resolved.

Turns out Comcast installed a new moden recently and left its modem's firewall active.

[Retired_Member]

Can or did you test from outside your home network ....Nat loopback is blocked with netgear routers, It's probably working from outside local but cannot be reached from inside.

[jhinkle]

It's not working from outside, that's why I'm attempting to find out why.

The client is part of a software report package that has been working with my customers for 15 yesrs now.

The only thing I have done is moved my server application from a paid Hostgater server to my own computer behind the R8000 router.

Currently, there is no communication with the outside world.

Any suggestions?

[jhinkle · Accepted solution]

Thanks for reply -- issue resolved.

Turns out Comcast installed a new moden recently and left its modem's firewall active.