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TurboPGT's profile

Scholar

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47 Messages

Wednesday, March 30th, 2022 3:51 PM

Closed

Port forward to specific internal port with BGW320????

Port forwarding is this: You choose a public port, or range. You choose a private IP and port. Public forwards to private.

In this absurd router, you can only choose a "device" to forward public ports to. Not even an IP, just device. And no port. How am I supposed to forward ports when I can't choose the internal port? The public port must always match the internal? That's not how firewalls or port forwarding work anywhere else in the world.

What am I missing here? Is this thing really this gimped? With this limitation I can only have ONE device on the entire network listening on a port. I have multiple devices that need to listen on 5900 for VNC (and changing this is not possible or practical).

There is also no automatic port forwarding with UPnP, so this is incredibly limiting.

Accepted Solution

Official Solution

ACE - Guru

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9.9K Messages

2 years ago

Yeah, that's exactly what IP Passthrough does. I guess the drawback is that because the gateway is not truly in "bridge mode" it still does have some role in the processes.  There shouldn't be any performance drawbacks although we do occasionally see people in here that complain about weird download/upload speed issues.  I don't think we've ever traced any of those back to the IP Passthrough process itself.

One thing to keep in mind is that we suggest doing a factory reset on the gateway before attempting to do IP Passthrough (and port forwarding, for that matter) because we've seen too many oddball issues setting it up and the reset always seems to correct those problems.

ACE - Guru

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9.9K Messages

2 years ago

Well, the AT&T gateways do have some serious deficiencies but in this case I think you're just looking in the wrong place.  That sounds like you're in IP Passthrough, which is primarily used when you want to use your own router in addition to the gateway.

What you're looking for, port forwarding, is in the NAT/Gaming section.  Take a look at THIS guide (use the BGW210 since AT&T hasn't updated the page).

Scholar

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47 Messages

2 years ago

Thanks for the response. I am pretty familiar with port forwarding and port mapping, but this is the first time I've come across a router that has a such a limited version of it. Identifying both public and private ports for the map is not very advanced or unusual, it is the standard.

I haven't looked at the IP Passthrough options yet. Does that imply passing through the public IP to the WAN port of another router, which can then take over DCHP and port mapping/forwarding work? Are there any drawbacks or performance concerns when using this on these devices?

Cheers.

Community Support

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231.2K Messages

2 years ago

Hey TurboPGT, we understand that you're needing help with answers to your question. As the ace stated port forwarding would be the best option.

 

When you setup port forwarding the secondary router would take control of the network as you stated. Then all functions would be control by the secondary router.

 

Please let us know if that answers your question.

 

Charles, AT&T Community Forums

 

 

Scholar

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47 Messages

2 years ago

Ok thanks.

ACE - Expert

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35K Messages

2 years ago

@TurboPGT  Sigh (for Charles reply... I'm sorry about that).

Port Forwarding does what you think.  It allows you to forward specified ports to a specified device, doing PAT if you wish.

IP passthrough is sort-of bridge mode.  It hands your router the public address when it requests an IP via DHCP, it passes all unsolicited traffic from the WAN interface to that node, and it passes traffic from that node to the Internet without NAT (though it does maintain a session table).

New Member

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2 Messages

2 months ago

This  works limited    both port forward and passthrough.   Most firewalls   can detect all traffic  destined to the wan interface..   But ATT  rules  only work  for people  outside destined in.. 

if i use a public ip address  set in cloudflare or external  DNS provider,    and it resolves to my att modem/router    all public fraffic will work..   

however the people on the lan would not ,  this router isnt smart enough to make that same rule apply to them.  i do  not even see that traffic logged..   

  i guess the packets misteriouslly disapears.

This lack of options  required the interal lan to have its own dns server.   and not use an isp dns..    this option (Edited per community guidelines) 

(edited)

ACE - Expert

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35K Messages

2 months ago

Routing internal traffic with a destination IP of the Public NAT address back into the local network is called NAT loopback or NAT hairpinning.  The AT&T Gateway will not do it.  However, if you have your own router behind the AT&T Gateway in IP Passthrough mode from the Gateway, it can do the loopback itself.

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