more port forwarding ports opening 'on their own'
alf2016a
Enthusiast - Level 2

I opened a few ports for File sharing on the mac which work ok, but keep noticing additional ports opening for this Mac but not others on the network:

UPnP IGD UDP 50675
UDP Any -> 50675

and

UPnP IGD UDP 55670
UDP Any -> 55670

Is Verizon opening ports for some reason on my Verizon router FiOS-G1100 ? When I first got the router, Verizon Tech support had me (unnecessarily) download and open "Double-Click To Start Support Session" which was in a file called "Bomgar".  I trashed it after the session but did it install something in my OS that is now controlling port forwarding?  Trying not to get paranoid about this.  And I don't want to waste a lot of time reinstalling OS to remove potential risky hidden software.

thanks

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Correct answers
Re: more port forwarding ports opening 'on their own'
lasagna
Community Leader
Community Leader

It's likely that UPnP is enabled on your router.   This was a standard developed which allows local network devices to intelligently communicate with routers to automatically open port forwards to enable operation of their services.

Unfortunately, some "services" have a higher opinion of themselves or the level of intended operably you desired and open ports that either are not required for your intended method of using the application or which can be worked around.   UPnP is also an attack vector for malware to open backdoor ports into a network to allow external access.

From a security standpoint, it's BAD to enable UPnP.  From a ease of use perspective (i.e. ignore security concerns and good practices) it makes things easier for the less technically savvy.

Good news ... you can and should disable UPnP on your router (depending on the router, it's probably in the advanced settings somewhere).  That will turn off the behavior your are seeing.   Note that there are a few ports that Verizon opens to allow them to talk to your STB's for TV, so those will appear regardless.

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Re: more port forwarding ports opening 'on their own'
lasagna
Community Leader
Community Leader

It's likely that UPnP is enabled on your router.   This was a standard developed which allows local network devices to intelligently communicate with routers to automatically open port forwards to enable operation of their services.

Unfortunately, some "services" have a higher opinion of themselves or the level of intended operably you desired and open ports that either are not required for your intended method of using the application or which can be worked around.   UPnP is also an attack vector for malware to open backdoor ports into a network to allow external access.

From a security standpoint, it's BAD to enable UPnP.  From a ease of use perspective (i.e. ignore security concerns and good practices) it makes things easier for the less technically savvy.

Good news ... you can and should disable UPnP on your router (depending on the router, it's probably in the advanced settings somewhere).  That will turn off the behavior your are seeing.   Note that there are a few ports that Verizon opens to allow them to talk to your STB's for TV, so those will appear regardless.

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