The MAC Pass-through feature allows a device on the LAN to have a public address assigned to it. All other client devices will connect using NAPT on the private LAN subnet. MAC Pass-through is used when a port number or packet protocol that an in-bound application might use cannot be anticipated. For example, some network games select arbitrary port numbers when a connection is opened. This feature may also need to be used when connecting multiple gaming systems to the Internet at the same time. This document provides steps to pass through a WAN IP address to a connected device.
CAUTION: When a client device is setup for MAC Pass-through, it will be fully accessible from the Internet. For security purposes, please make sure that the device is protected by a software firewall.
NOTE: When a device is setup for MAC Pass-through, it will be inaccessible from other client devices connected to the gateway.
Requirements
- Subscribe to additional Internet IP address from the cable provider, up to 32 IP addresses supported.
- Client device MAC address, which can be gathered from the client device or in the Web manager of the SBG6580.
- Client device network configuration set to obtain an IP address automatically via DHCP (normally the default setting).
Enable MAC Pass-through
- Launch a web browser, such as Internet Explorer, Firefox, or Safari.  Enter http://192.168.0.1 into the address box, and press the Enter key. The Login page will appear.
 - On the Login page, enter admin in the Username field.
 - Enter motorola in the Password field.
 - Click the Login button.  The Home page will appear.
NOTE: On firmware version 8.9.0.4 and later, the default admin password is required to be changed. Â The Change User Password prompt will immediately appear after logging into the Web manager with the default admin password. Â For assistance with the Change User Password screen, please refer to article # 18055 - SBG6580 (v.8.9.x): Prompt to Change Default Admin Login.
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 - Move the mouse-cursor over Advanced on the main menu and click the Options link on the sub-menu.  The Advanced - Options page will appear.
 - On the Advanced Options page, scroll to the bottom of the page to the Pass-through MAC Addresses section.
 - In the Pass-through MAC Addresses section, enter the MAC address of the device to pass the WAN IP address to, then click on Add MAC Address.
 - To stop passing through the WAN IP address to a device, click on the MAC address in the list, then click on Remove MAC address.