Port forwarding to an old DEC VAX machine with no wifi or DHCP

So desperation is the mother of invention, to twist a phrase.

I determined the Xfinity app's problem is that it only shows a list of target systems to receive the port forward that are connected by DHCP.

Then I figured out that VMS 7.3 does support a DHCP client. So I:

Turned that on for my Ethernet interface using TCPIP$CONFIG, stopped and then started TCPIP

Got a warning message on TCPIP startup that the static IP I had was being ignored

On another computer on the local network, I did a Telnet to the local address assigned by DHCP. 

It worked just as well as when I had the static address

Then go to the Xfinity app on your phone

Click the WiFi icon at the bottom of the screen (yes, I know the connection wanted is through Ethernet, but this is part of the app's bug)

Chose View WiFi equipment

Then Advanced Settings

Then Port Forwarding

Read the warning at the bottom of the next screen and click the black button Add Port Forward

Then in the pull-down list for the device to receive the Port Forward, there was my Ethernet connected VMS system's node name!

Next step - choose Manual Setup

Change the Port Number from the default of 1 to 23 (the standard Telnet Port)

Then choose TCP

and then you're done

Now to really prove the VAX is now accessible on the Internet, you need to be external to your home internet.

So use your cell phone

Turn off the WiFi on your cell phone in its Settings

Then Telnet to your WAN address - plenty of free websites such as http://wanip.info/ will tell you your WAN address

You could also log in to your Comcast modem and get the same answer.

Then run a telnet app on your phone - I use Mocha Telnet

With the phone's WiFi off, the connection will be made through the carrier's Internet interface, which is outside of your ISP's domain.

And sure enough, you're in

Greetings, dbster! We appreciate your post and sharing how you got your port forwarding issue figured out with the hardwired setup steps taken. Sounds like a solid approach. You rock! Let us know if you have any additional questions or concerns in the near future, as we are always happy to help on our XFINITY Community Forum. Take care!