Deco M9 and AT&T Modem Passthrough Issues

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Deco M9 and AT&T Modem Passthrough Issues

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Deco M9 and AT&T Modem Passthrough Issues
Deco M9 and AT&T Modem Passthrough Issues
2023-11-02 21:14:08 - last edited 2023-11-06 22:02:29
Model: Deco M9 Plus  
Hardware Version: V2
Firmware Version: 1.6.2

Hi, I'm trying to get my Deco M9 to work in IP Passthrough mode with my AT&T BGW320-505 router for port forwarding. Following a process I've seen recommended for this modem that instructs setting up the modem as in the screenshot below, I am having not having the same luck. Has anyone had luck getting this to work with this mesh/modem combo?

 

One possible issue is that the MAC address seen in the modem's client list (populated in the highlighted field below) is different from what's in the Deco app. I've seen that Decos can have multiple MAC addresses based on their connection method (LAN/2.4/5 GHz), and that one user had success by finding and trying the different MACs. Could anyone tell me how to find the different MAC addresses to try? Thanks in advance.

 

7a208d5c43784d62a515847e2ebd223a

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Re:Deco M9 and AT&T Modem Passthrough Issues-Solution
2023-11-05 16:43:29 - last edited 2023-11-06 22:02:33

  @HowGee I believe the DHCP-fixed mode is beneficial when you have several devices connected to the modem.  In that case, you want, indeed, to control to which device you assign the WAN IP of the modem.

Did you try the DHCP-dynamic method?

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Re:Deco M9 and AT&T Modem Passthrough Issues
2023-11-03 08:19:11

  @HowGee 

Hi, I see there is an option "Choose from list" and I think it might refer to its DHCP list. Can you see any device here matching with the IPV4 address on the Deco APP>More>Internet connection>IPV4?

And if you choose "Manual Entry", you could try the MAC Address on the product later of Deco+1 in hexadecimal.

such as XX-XX-XX-XX-XX-08-->XX-XX-XX-XX-XX-09.

 

Best regards.

 

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Re:Deco M9 and AT&T Modem Passthrough Issues
2023-11-03 17:16:29

  @David-TP thanks for your help. The main Deco (which is the only device connected to the modem) shows up in the "Choose from" list. That screenshot is below. The MAC address listed (ending in :20) is the one on the Deco+1 in hexadecimal (MAC printed on the product ends with :1F). I have tried both of these MACs, but none worked. Anything else I can try?  


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Re:Deco M9 and AT&T Modem Passthrough Issues-Solution
2023-11-05 16:43:29 - last edited 2023-11-06 22:02:33

  @HowGee I believe the DHCP-fixed mode is beneficial when you have several devices connected to the modem.  In that case, you want, indeed, to control to which device you assign the WAN IP of the modem.

Did you try the DHCP-dynamic method?

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Re:Deco M9 and AT&T Modem Passthrough Issues
2023-11-05 16:51:39 - last edited 2023-11-06 22:02:42

  @HowGee Is your Deco configured to obtain its IP address via DHCP?  What is its Internet Connection Type?

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Re:Deco M9 and AT&T Modem Passthrough Issues
2023-11-06 22:02:21

@yves_b, THANK YOU! The main Deco is the only device connected to the modem, and it was configured to obtain an IP via fixed allocation (not DHCP).

 

I changed it to obtain a dynamic IP and also switched the modem to the DHCP-dynamic method, as you suggested. And it looks like it worked! The device IP address of the Deco now matches my WAN IP , and the ports look open. Thanks much for the suggestions!

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