Cisco DPC3825 Upgrade -Basic Setup and Bridge Mode (Cable Modem Mode)
To explain in layman terms, you rnew Cisco DPC3825 functions as a cable modem AND a router, this may be all fine for new customers who don't have an existing router. But for customers upgrading from old cable modems that have your own router, you may or may not want to continue to use your own router. For many of us, the easiest choice is of course to plug the new Cisco DPC3825 in and connect it to your router and have everything working like before. There are 2 possible methods to do this.
Some people may be confused with the term "bridge mode" but it basically disables the router functions of your Cisco DPC3825, and makes it work exactly as your old cable modem.
After you plug in your new Cisco DPC3825 in the same configuration as your old cable modem (Power, Cable, Ethernet Cable from WAN Port 1 to your Router WAN. You will actually have to phone/call Rogers, go for Technical Support regarding your Internet Services and then press "6" for "other technical inquiries". Tell the representative that you just connected your new Cisco DPC3825 and you want them to put it into BRIDGE MODE for you. It'll take about 2-3 minutes, reset, and you should be able to connect to your old router's wireless access point just like before.
When in bridge mode, do not plug any other devices into the Ethernet ports of the Cisco DPC3825 except the one going to your router.
This process is reversible by holding the reset button at the back of the modem for 60 seconds, or by calling in again.
Some shipped versions of the DPC3825 may have the "Bridge Mode" options selectable from the router menu, this method may be a hit/miss as there are varying versions of the DPC3825. To do this, you will need to connect to http://192.168.0.1 through a direct wired connection, and the username password is NOT blank fields as mentioned in the manual in most cases. The default username in my case was: cusadmin and the password was password.
In the menu there may be an option to set the router in to Bridge Mode, you may or may not find it. Mine's didn't have it despite checking all the setting pages, but user TenzoR and other forums have reported some this is possible to achieve on some DPC3825's that do not have this function disabled by the OEM. So, if you don't find it in the menus, don't worry, just follow Method 1 and call in to your ISP and they'll do it remotely.
For any others who might be attempting to setup their Cisco DPC3825 to use as a router, you may or may not want to "test" it out and compare the speeds and stability to your old router before considering Bridge Mode. Again, you will need to connect to http://192.168.0.1 through a wired connection, and the username password is NOT blank fields as mentioned in the manual in most cases. The default username in my case was: cusadmin and the password was password. There have been mixed reviews, speed wise it is definitely capable of handling all that Rogers/Shaw Extreme internet offers, but for me, I wanted the stability and other functions offered by my original router.
I hope this post has made your configuration easier!
Edited: To include 2nd possible method.