Have no internet when setting up W121 ax6600 router connected toT25 modem

Also noticed that the light band only lights up on the back sides and not all the way around. Wonder it that’s a sign they are defective. Also tried two different 12V 2.5A power adapters. Is that normal for these?

Noticed my WIFI info is wrong on gateway/DNS on phone with app. Device my not be resetting, clearing out cmos or writing in new data.

Scrape my 2nd and 3rd reply as I’m struggling with this setup. Simply put I can’t connect to wifi on my cell phone that has the SB app on it. I don’t think I like not having access to settings. Get all the way to the end of setup and can’t connect to register and finish setup. Frustrating! Arris T25 modem/Arris W21 mesh router should be easy, right?

If the internet connection is not working and you are being redirected to an Xfinity activation page, this indicates that the modem is not properly provisioned. In this case, we recommend reprovisioning the modem with your internet service provider. 

To isolate the issue with the internet connection, follow these steps:

1. Turn off the W121 and set it aside.

2. Connect the T25 directly to your computer using an Ethernet cable. Ensure that the T25 has only this single Ethernet connection to your computer.

3. Restart the T25 and confirm if the internet connection is working on your computer.

Once you have confirmed the internet connection is working:

1. Turn off the T25.

2. Disconnect the Ethernet cable from your computer and connect it to the WAN port of the W121.

3. First, turn on the T25 and wait for it to fully boot up. Then, power on the W21 and proceed with the setup.

Thank you so much for your reply.

When I connect T25 directly to PC as you suggested I still get no internet.  I did have Xfinity reactivate the modem once before last week when I had the W121 connected but it still didn’t work. I’ll try again and follow your exact steps.

Thing is if I go back to my Netgear 1750ac R6400v2 router connected to T25 everything works fine. Would like to upgrade to W121 mesh. 

What setting/s in the T25 modem is causing this?

Do you know if Xfinity takes complete control over modem settings or do they allow users to make changes?

When I do try to get into T25 modem settings advanced features I get: 

In order to access advanced features you must enter the password of the day:

How do I get this password? 

Thanks

Adding to my most recent reply. When I connect T25 directly to the ethernet card of my PC do I need to setup a static IP address on modem? PC setup for Dynamic IP address handling. Again no access to T25 modem configuration. Thanks

Since you're unable to access the internet on the T25, could you please confirm whether the T25 is connected only to the computer or if there are any other devices connected via Ethernet?

Also, kindly check and share the LED light status on the T25. Additionally, please verify the IPv4 address, perform a modem reset, and then check if the internet connection is restored.

Ethernet cable from T25 connected directly to PC no other cables.

POWER ON, US/DS, ONLINE, TEL 1 LED’s - ON.

CMD prompt ipconfig below: 

   Connection-specific DNS Suffix  . : hsd1.fl.comcast.net.
   IPv6 Address. . . . . . . . . . . : 2001:558:6004:e:4e:305c:6f03:8f9f
   Link-local IPv6 Address . . . . . : fe80::ada6:97b7:da83:5ea6%9
   IPv4 Address. . . . . . . . . . . : 73.120.188.78
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : fe80::201:5cff:fea9:2646%9
                                       73.120.188.1

No Internet and Xfinity screen come up.

Reset T25 same thing.

--------------------------------------------------------------------

ipconfig when T25 is connected to Netgear R6400v2

  Connection-specific DNS Suffix  . :
   Link-local IPv6 Address . . . . . : fe80::ada6:97b7:da83:5ea6%9
   IPv4 Address. . . . . . . . . . . : 192.168.1.8
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.1.1

everything works great with Netgear but I want to upgrade to W121 mesh

Thanks

Thank you again for sharing the information. Please try contacting the ISP to reprovision the modem by deactivating the MAC address and reactivating the same.

Should I do that with the Ethernet cable connected directly to the PC or should I connect T25 to one of the W21’s WAN port and connect the LAN port of W21 to the PC? Tried this once already with Xfinity and W121 or ethernet directly to PC didn’t work but I’ll try again.

SURFboard Moderator - WIFI Warriors Thank you so much for your help.

Got it to work without calling Xfinity Support.

Instead of unplugging the T25 modem to reset I went through the Xfinity App and re-did the Provision/Activation.

1. I turned OFF the Netgear router and unplugged the ethernet cable going to PC and plugged into LAN of W21 router.  (So LAN of W21 to PC ethernet plug)

2. I moved WAN from the Netgear to the WAN of the W21(Yellow) coming from the T25. (So one of the ethernet plugs of T25 to W21 WAN)

3. Turned ON W21 router.

4. In the Xfinity App went to Services/Activate more devices/Your Equipment and did the modem/router setup again. 

Internet came on PC after Power, US/DS, Online and Tel 1 were all solid ON. (I have one phone line). Still had to reset W21 router once or twice but it finally connected.