UPnP on guest network

ClarkS Member Posts: 2
First Comment Photogenic
I recently added a Playstation PS4 to my network. My Fingbox quickly found a bunch of open ports. So I then when into my Synology router and disabled PnP. That eliminated a bunch of open ports. But then the PS4 could not go online. Later I moved my PS4 to the routers guest wifi network. The Fingbox port test still shows there are no open ports. And the Synology router still has PnP deactivated on the main network. However the Fingbox is still warning that PnP is in use. How does it still see it even though PnP appears to be restricted to only the Guest wifi network?


  • rooted
    rooted Gulf Coast, USModerator Posts: 893
    250 Likes 500 Comments 50 Answers Second Anniversary

    UPnP announces itself network wide but if the guest network was truly separate from the internal LAN Fingbox wouldn't see it.

    You say UPnP is disabled but then you say UPnP appears to be restricted to the guest network, my guess is the UPnP switch doesn't affect the guest network or you need to reboot the devices due to a miscommunication about the status of UPnP or some such issue.

    [Deleted User]
  • The user and all related content has been deleted.
  • ClarkS
    ClarkS Member Posts: 2
    First Comment Photogenic
    Not exactly. Let me explain my situation better. 
    1. I recently got a PS4 and placed it on my wifi network. Fing quickly found it had opened several ports using UPnP. 
    2. My router GUI showed there were indeed several ports open. I reconfigured my router to turn off UPnP. The router verified there were no longer any open ports. However the PS4 no longer could connect to the internet.
    3. So I enabled the Guest wifi network on the router and moved the PS4 to the guest network. The PS4 was now able to connect to the network and the router still showed no open ports
    4. I again ran the Fing analyzer. It showed no open ports but it did show that port forwarding was enabled. There are no open ports shown in the router and the router says UPnP is disabled. But I do know some ports in the guest network must be open and so therefore UPnP must be enabled there or the PS4 would not be able to connect. 
    So somehow the Fing device must know about the open ports in the guest network and I still wonder how it would know that. 

  • Scooby
    Scooby Member Posts: 178
    25 Answers 100 Comments 25 Awesomes 25 Likes
    edited December 26, 2019 #5
    Some routers have the option to "allow/enable" the guest network to access the local network. For a Synology router, it might be found here:
    Is it possible that option is "enabled" on your router? If so, it could explain how the Fingbox could see open ports on the guest network.
    With the "Media Player" app, the PS4 can play content from DNLA compliant devices. DNLA uses port 1900, which is the UPnP port. If you have "Media Player" installed on your PS4, it may have port 1900 open. If Fing "sees" that port open, it may think you have UPnP running on your network/router, even though it is just from your PS4. When you do a "Port Scan", with the Fing app, it can find ports opened "locally", especially if they are on your "local network".
    Just a thought.

  • GadgetVirtuoso
    GadgetVirtuoso Member Posts: 21
    10 Comments First Anniversary 5 Likes Founder
    Typically guest networks are isolated networks, meaning devices on those networks can't communicate with each other on that network (east-west traffic). Your Fing box also wouldn't know about your guest network because it is on a different subnet from your home network. What your Fingbox could be picking up is UPnP and open ports on other devices on your home network. Things like printers, NAS, cameras, and more often have open ports and have UPnP services running on them. Printers are especially bad about this kind of thing because they often offer direct printing services such as AIrPrint.