Creating Virtual Routers for the CMTS Device (C-Web Interface)
You need to add a virtual router object called default to the CMTS device.
To add a virtual router to an existing router:
Click Configure, expand Shared>Network, and then click a CMTS device.
The Device pane appears.
From the Create new list, select Virtual Router.
Type a name for the new device in the dialog box, and click OK.
The Virtual Router pane appears.
Click Create, enter information as described in the Help text in the main pane, and then click Apply.