XFI and Port Forwarding

I think I have figured out the new xFi port forwarding feature.  

Unlike the way port forwarding has worked since the beginning of time xFinity has changed to a web page approach that works very different.  And in fact is far more insecure. And can be maddeningly frustrating.  

Previously every router port forwarding feature was done by typing in a list of IP addresses and their corresponding TCP ports to the gateway/router/modem. The router then matches outside requests for that port to the LAN IP of the device.

The xFi port forwarding no longer uses the LAN IP addresses in the setup list.

Rather it uses a list of names it creates from the DHCP assignments. And it deduces names of these devices from their responses to queries. This new method creates problems.

Obviously the device may be turned off for a period of time longer than the DHCP lease and when turned back on may be assigned a different IP address. That will work fine as long at the name deduced for the device is the same as when Port Forwarding was initially setup. So the port forward will be automatically adjusted to the new DHCP assigned IP address. Plus it appears that the Port Forwarding list also matches to the MAC address which is permanent and does not change even if the device is off for years.  MAC addresses are unique to every device on Earth (and surely we are going to run out soon.)

So this means that port forwarding will only work on DHCP devices!! Often it is difficult to determine what device has which IP address. Previously you went into the setup for the device and assigned it a hard IP address that was not in the DHCP range. It was entirely up to you to police your LAN and make sure you don't have collisions by assigning two devices the same IP address. Not a problem for someone who actually understands port forwarding. xFinity has attempted to make this easier for the gentle user.  But often the gentle user doesn't understand port forwarding so making it easier can create troubles.

Now here is the big problem. When initially setting up port forwarding you have to choose the device you want from the list of names. If you don't recognize the name then you are stuck with no straight forward solution. Often the name in the list for a device is not the name you know for that device. Nor is it even vaguely similar to what you would expect to find. And often there are several names that are gobbledygook. And worse yet is you might have multiple devices like IPCameras that all return the same name.

So which device do you choose to setup port forward?

If the list showed you not only the name but also the IP address and MAC address if would be a great help. But if the IP address is DHCP assigned then you have to use some method to find the IP address of each device. Sometimes you can query the device and ask it directly what it's IP address is. Most of the time you can't. Or you can go into a list of assigned devices on the xFinity modem(gateway) and see a list of names and IP addresses. But these names are often as unrecognizable as the list provided in Port Forwarding. I have no real comprehensive solution for this problem. In the case of my IP cameras Foscam has a search tool which finds all the Foscam cameras and lists their names you have assigned them and their IP addresses. Good luck on your other devices. Even turning them off and only having one on at a time can be a problem because the xFinity modem remembers the device and keeps it in the list.

You can't see the IP address for a device in the Port Forwarding list until you have actually assigned it a port.

So you have to guess. You select a name that you think might be your device. You assign a port to it. Don't even bother at this point with the real TCP port. Just use the default 1. After the port has been assigned you can observe the Port Forwarding list and click Show Port Forwards to reveal the IP address and the port number. If you have deduced the IP address of the device you wish to setup and the port you just added has that IP address you can now change the TCP port to the one you want for that device and you are in business. If you don't recognize the IP address as something you were trying to port forward then delete it and try another name.  It would be nice if xFi allowed me to assign an identifying name to the device at least after assigning the TCP port. Like the gateway setup used to let me do. But, alas, it does not have that feature.  So in a few months you will likely forget those odd names and to which device they corresponded. So you will need to write down a list somewhere and not lose it.

In my case I had numerous devices in the list with the same names. I knew the IP addresses for each camera since the Foscam Search Tool had revealed all to me. I randomly selected a device from the drop down list. I setup the TCP for port 1 and saved. Then I went into the Port Forward list and observed the device's IP address and I setup the correct TCP port for that device. Then I had to do a second one. But how do I select the next device from the list and not select an already setup device or even the one I just did since the list contains 4 devices with the same name and the order does not stay the same? Dumb luck. Repeated tries. And lots of cussing.

I have the same problem so if you get a solution please post it. By the way Xfinity support is WORTHLESS.