Shared Knowledge

"Slingbox - Suddenly Can Not Be Found When Trying to Connect Remotely"

21 February 2011


Summary: when a Slingbox is set up, a port is opened in router to allow commands to be sent over the Internet to the Slingbox, but if the IP address of Slingbox is not reserved or fixed in router, at loss of power or power cycle of the router, a new IP address could be assigned to the Slingbox that is not linked to the open port and remote communications with the Slingbox is lost.




Every device, to include Slingbox, on a home network has a fixed, unique, media access control or MAC number. This number is built into the hardwire of the device and can not be changed. The MAC number or address of a device can be found on a sticker on the device.

Every device on a home network has a unique Internet protocol (IP) number or address.

In most cases, the router of a home network automatically assigns IP address to networked devices.

By default, as security measure, home routers prohibit commands to come from the Internet and interact with any home networked device.


Slingbox setup:

When a Slingbox is added to a home network, the router automatically assigns it an IP address.

With an IP address assigned, a personal computer (PC) on the same home network, running the Slingplayer application, should be able to connect to and control a networked Slingbox.

To allow the Slingbox to be controlled remotely via the Internet, the router must be told to allow commands to come from the Internet and be sent to the Slingbox.

When you run Slingbox setup, it tries to tell the router to accept commands from the Internet for the Slingbox by opening what is known as a "port" inside the router.

Depending on the router, sometimes Slingbox setup of a port in the router is successful and other times not.

When Slingbox's automatic setup of a port in the router is not successful, a port has to be manually opened in the router by going into the router and finding the section on ports and defining an open port at what is known as UDF 5000.

When a port is defined for a Slingbox, the port is associated with both the MAC and IP address of the Slingbox.

Unfortunately, if the IP address of the Slingbox is not reserved or fixed inside the router, at a power outage or power cycle of the router, the router could assign the Slingbox a new or different IP address than the one used in the open port definition. If this happens, communications over the Internet with the Slingbox is lost.  PC's on your home network would still have Slingbox access and control because they do not use the router port.

How you get into your router and where inside your router you fix or reserve the IP address of the router varies from router to router.

Many routers can be entered by typing in the Windows Explorer address bar either or and then entering a user name and password.


This shows that the IP address of my 2 Slingboxes have been fixed and reserved in my Dlink router. If power is lost, when the router comes back alive and begins to assign IP addresses to network devices, it knows to assign the fixed IP address defined by the Slingbox MAC number. Again, where and how you reserve IP addresses are router make and model dependent.

Slingbox - Setting up for inside a router.


Below shows the 2 ports I have open in my router for my 2 Slingboxes to be controlled over the Internet.

Slingbox - Setting up for inside a router.