NETGEAR is aware of a growing number of phone and online scams. To learn how to stay safe click here.
Forum Discussion
NAT Hairpinning/Loopback Not Working
I have noticed that NAT hair pinning only seems to work with *manual* port mapping, not UPnP / NAT-PMP.
3 Replies
A fascinating thought. Want to experiment with this. However.........
I know how to test NAT Loopback (hairpinning) by deliberately forwarding ports through the Orbi firewall. That works.
My guess is that UPnP Loopback can be tested by:
- Enabling UPnP in the Orbi Advanced Menu
- Installing some device/software that opens ports using UPnP
(the ports forwarded would show up in the UPnP table)
Can you suggest how a person can test UPnP Loopback?
Your guesses are correct.
Any UPnP (or NAT-PMP) application would suffice to reproduce the issue. I used Port Map for macOS https://www.codingmonkeys.de/portmap/ but really any would have the same effect, since the option to hairpin is not part of the UPnP or NAT-PMP protocols.
Thanks for the quick response. "Over my head" (oh, dear). Being a Philistine (Windows user), it is not clear to me how to activate UPnP and demonstrate that it is actually working. My example (see messages above) about the Epson printer was based on the printer already having an http web server.
Do I need to set up a web server on my Windows PC that can use UPnP to open a port? Or.......????
I'd really like to validate that ports forwarded because UPnP opened them behave differently than ports opened deliberately, but have no clue how to do it.
If ignorance is bliss, then I must be in heaven.
