Skip to main content
Question

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


Forum|alt.badge.img+1

Have a Arris T25 cable modem with Xfinity 600mbps Internet/Voice plan.  I have a Netgear 6400v2 ac1750 router and everything runs great. I want to replace the Netgear router with a mesh W121 MAX ax6600 (P/N WR00ZAE21DB) which I have two units as one will be a satellite. I run the Surfboard Central App and follow directions (power down modem and router, modem cable to WAN of W21...) and go through the setup process fine until I get to end where it wants me to connect to newly created SSID which I called (Buddie’s) with my new password which I entered 100% correct. Can’t connect to the WIFI and am thrown to the Xfinity activation screen. W21 router blinks green and white at this time and when I checked Xfinity app to activate T25 modem it says I do not have an Internet plan when I do (Message from Xfinity app: (“You need xfinity internet to continue” exit activation). I did a chat with Xfinity and had them activate the modem but still couldn’t connect W21. I tried this with both w21 units with the same result. W21 never turns blue just mostly blinks green and white. Error codes from app are 0000-1303 and 0003-1003. Tried 2 different ethernet cables from modem to WAN of router (they both work fine with Netgear router). Any ideas? I’ve tried around 10X to connect through SB app. Any help would be much appreciated. 

6 replies

Forum|alt.badge.img+1
  • Author
  • The Many
  • 5 replies
  • May 27, 2025

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?


Forum|alt.badge.img+1
  • Author
  • The Many
  • 5 replies
  • May 27, 2025

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.


Forum|alt.badge.img+1
  • Author
  • The Many
  • 5 replies
  • May 27, 2025

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?


Forum|alt.badge.img+42

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.


Forum|alt.badge.img+1
  • Author
  • The Many
  • 5 replies
  • June 3, 2025

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


Forum|alt.badge.img+1
  • Author
  • The Many
  • 5 replies
  • June 3, 2025

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


Reply


Cookie policy

We use cookies to enhance and personalize your experience. If you accept you agree to our full cookie policy. Learn more about our cookies.

 
Cookie settings