Get superfast AT&T Fiber internet
sdegonge's profile



3 Messages

Wednesday, December 2nd, 2020 2:15 PM

BGW210-700 IP Passthrough to router works but PORT FORWARDING DOES NOT WORK

I've set a separate router to handle WIFI and DHCP instead of using the ATT modem.  IP Passthrough has been set up and everything is working fine as far as that goes. The problem is with port forwarding.  It just doesn't work.  I've searched this forum and scoured the interweb but found no solution.  My current configuration is shown below.  I've also tried different packet filter configurations but had no luck.  Any help would be appreciated!

Note that prior to this I was using only the BGW210-700 and port forwarding to my devices worked fine.

I'm now configured as follows...

Fiber <----->ONT PORT (BGW210-700) PORT1<----->WAN PORT (DLink DIR-842) PORTx <-----> My Devices  

BGW210-700 Configuration
Manufacturer ARRIS
Model Number BGW210-700
Software Version 2.8.7
Hardware Version 02001C0046004D
Broadband Connection Source ETHERNET
Broadband Connection Up
Broadband Network Type Lightspeed
Broadband IPv4 Address
Gateway IPv4 Address
Primary DNS
Secondary DNS


Private LAN Subnet:
DHCP Server ON 

Firewall Status:
Packet Filter Off
IP Passthrough On
NAT Default Server Off
Firewall Advanced Off

IP Passthrough Config:
40:9b:xx:xx:xx:xx (My DIR-842 router)
DHCP Lease 99 Days

DLink DIR-842 Router Configuration:
Cable Status: Connected
Connection Type: Dynamic IP (DHCP)
Network Status: Connected
MAC Address: 40:9B:xx:xx:xx:xx
IP Address:
Subnet Mask:
Default Gateway:
Primary DNS Server:
Secondary DNS Server: 

LAN IP Address:
DHCP Enabled

Port Forwarding:
MyDevice TCP 16500-16599 UDP 16500-16599 Enabled  



3 Messages

2 years ago

>Do you have any Firewall setting enabled on your D-Link such as IPV4/IPV6 Rules?


>How are you testing port forwarding?

Testing port forwarding with

>TCP 16500-16599 UDP 16500-16599 will be passed to your local LAN device You also have a program running and listening on those ports?


My device was still pointing to the ATT modem as the gateway.  I changed it to the DLink and all is well!

Thanks for the suggestions.  It pointed me to the problem.  I've been trying to figure this out for hours and I was convinced that the problem was with the modem or router.  Never thought to check the end device configuration.

New Member


4 Messages

3 months ago

   Did anybody find a solution to this problem? I'm having the same (‎Port forwarding behind 2 routers | AT&T Community Forums ( Moreover, there are two aspects of this problem. One is when you test access when you are on the same network and another is when you are on a different network. In both cases it doesn't work but it doesn't work differently.

   If you are connected to the same network where your routers are it seems BGW210 tries to optimize IP resolution and gives "deeper" IP, so let's say there is internet IP x.x.x.x and then BGW210 and then the other router external IP and then its internal IP is and then finally your server IP you want forward ports to, it gives and of course port forwarding doesn't work. It would work if it were resolved into

   If you are connected to a different network, not related to one with your routers it just doesn't work, and I don't have a clue why. It seems tracert gets lost in resolution and it doesn't even come to the port forwarding problem but I'm still researching.

   Also, in my case port forwarding didn't work stable when it was setup on BGW210 when I was connected to the same network. It failed intermittently.

Not finding what you're looking for?
New to AT&T Community?
New to the AT&T Community? Start by visiting the Community How-To.
New to the AT&T Community?
Visit the Community How-To.