SBG6400 (v1.3.x): DMZ Host Setup

How do I setup a DMZ Host in the SBG6400 Cable Gateway? 

The DMZ Host feature allows the Gateway to forward all externally initiated IP traffic (TCP and UDP protocols only) to a default host on the LAN.

This document contains the following sections:

• Enabling the DMZ Host
• Disabling the DMZ Host

The following are a couple scenarios in which DMZ Host is useful:

• When the port number or protocol in an in-bound application cannot be anticipated.  For example, some network games select arbitrary port numbers when a connection is opened.
• When all unsolicited traffic needs to be forwarded to a specific device in the network.
• When an application does not work well with port triggering or port forwarding.

• The IP Address of the device is required to setup DMZ Host.  It can be found in the network settings of that device. 
   

Enabling the DMZ Host

1. Launch a Firefox or Safari browser.  Enter http://192.168.0.1 into the address box, and press the Enter key.  
   
   NOTE: A browser message on Chrome, Edge, Firefox, and Opera, may appear when accessing the Web Manager.  The message includes 192.168.01 uses an unsupported protocol and ERR_SSL_VERSION_OR_CIPHER_MISMATCH.  The Web Manager uses an earlier version of the TLS protocol and does not match the version allowed by the web browser.  Safari browsers on Apple PC and mobile devices are not impacted.  The workaround to access the Web Manager with a PC is to use the Firefox browser and set the TLS version to 1.  For workaround instructions refer to article # 19435 - 192.168.0.1 uses an unsupported protocol.
    
2. A security or private risk alert may appear on the web browser advising users to proceed with caution when accessing the Web Manager.  There is no risk in proceeding to the Web Manager.  For instructions to bypass the alert screen, refer to article # 18181 - Alert Message for Web Manager Access.
    
3. On the Login page, enter admin or a customized username in the Username field.
    
4. Enter password or a customized password in the Password field.
   
   NOTE: On later versions of the SBG6400, the Wi-Fi Security Key is used as the default admin password printed on the bottom white label.  For assistance with Web Manager Access, refer to article # 18730 – SBG6400: Web Manager Access.
   
   
    
5. Click the Login button.  The Home page will appear.
   
   
    
6. Move the mouse-cursor over Advanced on the top menu, and click the DMZ Host link from the drop-down submenu.  The Advanced - DMZ Host page will appear.
   
   
    
7. On the Advanced - DMZ Host page:
   a.   DMZ Host -  Enter the IP Address of the DMZ Host.  For example: if the IP address of the server is 192.168.0.2, then enter 2.
   b.  Click the Apply button.
   
   NOTE: A restart is not required, as the settings will immediately go into effect.
   
        

The SBG6400 Cable Gateway is now configured to enable a specific device on the LAN to be the DMZ host.

Disabling the DMZ Host

1. Launch a Firefox or Safari browser.  Enter http://192.168.0.1 into the address box, and press the Enter key.  
   
   NOTE: A browser message on Chrome, Edge, Firefox, and Opera, may appear when accessing the Web Manager.  The message includes 192.168.01 uses an unsupported protocol and ERR_SSL_VERSION_OR_CIPHER_MISMATCH.  The Web Manager uses an earlier version of the TLS protocol and does not match the version allowed by the web browser.  Safari browsers on Apple PC and mobile devices are not impacted.  The workaround to access the Web Manager with a PC is to use the Firefox browser and set the TLS version to 1.  For workaround instructions refer to article # 19435 - 192.168.0.1 uses an unsupported protocol.
    
2. A security or private risk alert may appear on the web browser advising users to proceed with caution when accessing the Web Manager.  There is no risk in proceeding to the Web Manager.  For instructions to bypass the alert screen, refer to article # 18181 - Alert Message for Web Manager Access.
    
3. On the Login page, enter admin or a customized username in the Username field.
    
4. Enter password or a customized password in the Password field.
   
   NOTE: On later versions of the SBG6400, the Wi-Fi Security Key is used as the default admin password printed on the bottom white label.  For assistance with Web Manager Access, refer to article # 18730 – SBG6400: Web Manager Access.
   
   
    
5. Click the Login button.  The Home page will appear.
   
   
    
6. Move the mouse-cursor over Advanced on the top menu, and click the DMZ Host link from the drop-down submenu.  The Advanced - DMZ Host page will appear.
   
   
    
7. On the Advanced - DMZ Host page:
   a.   DMZ Host - Enter 0.
   b.   Click the Apply button.
   
   NOTE: A restart is not required, as the settings will immediately go into effect.
   
   

The DMZ Host feature in the SBG6400 has now been disabled.