Tablo Connect, Ports, and Firewall on Receiving End?

When I originally bought my Tablo, I discovered that Tablo Connect wouldn’t function at my workplace due to Tablo Connect picking random-ish ports that wouldn’t be open at my workplace’s firewall. Today Tablo Connect is working for remote streaming, but I haven’t done anything with regards to setting Tablo Connect ports to ones I know are open at work. In other words, remote streaming here shouldn’t be working.

Is Tablo acting as an intermediary for the stream to change it to ports that are acceptable at the viewing site? Slingbox used to be able to do something like this with a “relay” connection to work around firewalls.

Your work’s firewall is probably has the Tablo Connect ports open now.
You can see which network ports are open to the Internet using this:

Enter the public IP address of your Tablo, and the Tablo Connect ports defined.
If the tool returns that the ports are open, then they really are open thru the firewall.

Highly doubtful the network team has the ports open on the firewall here.

Also, unless the Tablo Connect ports are manually set I believe the Tablo Connect ports aren’t revealed through the Tablo web GUI. Is there a way to tell what the ports are if they’re not manually set?

Yes check your router. It’s on the port forwarding page.

Easy way to find out:

The Tablo Connect ports are defined in the Tablo Settings, and looks something like this:

You can see mine are ports 21981, and 21980.
Yours can be different.

You just need to know the Tablo’s public IP address, and the public port numbers to use that port scanning tool.

Here’s my port scan results, which show my firewall is filtering (blocking) the 2 Tablo Connect ports:

Correct, the Tablo Connect ports are only displayed in the Tablo GUI, if Tablo Connect is enabled for that media player device.

Tablo Connect is working for remote streaming on which device?
That’s the device you check the Tablo Connect settings on to see which ports it’s using.

Once Tablo Connect is enabled and working properly he Settings page jusy says it is enabled and does not show the ports.


The port information is only visible if UPnP/NAT-PMP fails and I have the option to “manually” set my ports.

That sucks.

Ah, then if Tablo Connect is using UPnP/NAT-PMP, then that means the firewall has UPnP/NAT-PMP enabled, and dynamic port forwarding is occurring.

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Back to the original question:

  • My Tablo is dynamically setting up port forwarding on my home router via UPnP
  • My workplace has a firewall for outgoing connections
  • Most example manual configurations of Tablo port forwarding have the Tablo asking for ports in the 21000 or 31000 range
  • It’s highly doubtful that my workplace has opened outgoing connections to my home in those port ranges

Is Tablo Inc “assisting” the connection to my house?

No. Likely something changed with your work firewall.

Huh, no, this is apparently all me.

Back a few months ago I attempted to work around this issue by setting fixed port forwarding (80->80, 443->8887) at home that I knew were open at work, additionally I set up a DHCP reservation for the Tablo on my LAN. During testing I disabled UPnP on my router, bounced the Tablo, and set up the Tablo for remote access via manual port forwarding. I was able to get the Tablo functioning from work. I thought by cycling the “Remote Access” option in the Tablo settings, I’d go back to the 21000/31000 port ranges. However I never tore down the DHCP reservation and the 80/443 port forward. Apparently the UPnP negotiation from the Tablo must (intentionally or unintentionally) discover (or accept) the still-existing port forwarding.

I can verify this is the case by visiting my public IP on port 80 and I receive “Nuvyyo Tablo Server” as a response.

Probably did not intend to leave that all set up.

Tablo Connect is used only when the media player device, like a tablet, is outside the Tablo’s local network.
Tablo Connect requires the router inside its local network to have 2 ports openned, either by manual port forwarding setup, or UPnP (automatic).

Surprising the Tablo was able to use the forwarding of 80 and 443, since those are manually forwarded but the Tablo is (theoretically) setting up Tablo Connect via UPnP. I thought utilizing manually forwarded ports would require UPnP to fail and the ports to be set via the Tablo’s “Settings” GUI.

If UPnP is enabled on your router, the Tablo will try to setup port forwarding using that even if you have manually configured other ports.

The reason question is did you put those manual ports in your Tablo previously.

I did put the external/internal port pairs into the Tablo in the past.

I did a bit more testing:

  • Disabled the 80/443 port forwarding and cycled Tablo Connect off and then on. Tablo Connect reported as “ready”, but no longer responds to port 80 from the public Internet
  • Reenabled the 80/443 port forwarding and cycled Tablo Connect off and then on. Tablo Connect reported as “ready” and (again) responded to port 80 from the public Internet
  • I left a DHCP reservation on the router for the Tablo enabled during all tests

My best guess is that the Tablo tries to set remote access and requests a public/private port pair for its internal IP, and the router responds that it already has an external port forwarded for that internal port+IP. The Tablo appears to accept and use that already set-up forwarding.

Where is the Tablo?
At work, or at home.
Which router are you changing port forwarding settings on, work, or home?

Both the Tablo and the router are at home.