I recently activated Internet service using my own cable modem/router, an approved Arris SBG10. The install technician made a point to inform me that I was responsible for any firmware uppdates.
Arris support says: "It is important to note that firmware updates for cable modem devices are controlled exclusively by the internet service providers only. This is the case whether the unit is owned privately or leased through them, as a security precaution for users upstream of the connected device. The most up to date version of firmware for your device that is available with your ISP is to be automatically pushed to the unit from them. There are no firmware/software updates available to install or download for the device.
Xfinity support says:
This is a response to Paul_M's post regarding firmware updates to customer supplied modem.
It appears that Comcast is not being transparent regarding their firmware update policy.
Arris 2nd level support has told me in no undertain terms that the ISP (Comcast) provides all of their firmware updates. I'd discovered a bug that Arris had fixed. Arris assured me that the fix would be pushed out to all Arris modems as part of their regularly scheduled firmware update.
Comast, on the other hand and as you'd noted, leads you to believe that only Comcast rental modems will get firmware updates. I've gone back-n-forth with Comcast about his matter, most recently today when I wanted to know if the bug fix has been pushed out in a firmware update. Their latest caveat is that only WiFi enabled customer owned modems will get firmware updates from Comcast. Other than that, customer supplied/owned, Comcast designated acceptable, modems will get firmware updates. See the last part of my chat session below.
Hope this helps.
1:43:39 PM Val : Joshua, You just told me that my WiFi enabled modem is part
of Comcast's regularly scheduled firmware updates. Now, you're telling me
otherwise. Which is it?
1:45:33 PM Joshua : That is right, Val. We can push for firmware update so
long as there is new firmware version for your modem. Also, if ever our tools
cannot push the update, that's the time we need your help calling your
modem's manufacturer so we can let them check the status of the owned
modem and let them push it on your behalf.
1:47:17 PM Val : OK ... just so I have a clear understanding ... my owned (non-
Comcast rental) WiFi enabled modem will get regularly scheduled firmware
updates from Comcast. Correct?
1:48:28 PM Joshua : You got that right, Val!