UPnP and port-forwarding question

Ichinisan

Lifer
Oct 9, 2002
28,298
1,235
136
I noticed that my Seagate network HDD is responding to port 80 requests from WAN and displays a log-in page. My router (currently running Tomato firmware) shows that port 80 was opened through UPnP and forwarded to the network drive. I occasionally experiment with temporary web servers and such, so I sometimes need port 80 forwarded to another system/device on my LAN. It made me wonder:
What does the router do when two UPnP LAN devices request the same WAN port? Are UPnP devices notified when there's a conflict with another UPnP device using the same port?​

I assume manually-configured port-forwarding overrides UPnP in any case (though I haven't tested it). Just curious if anyone knows more about this.
 

VirtualLarry

No Lifer
Aug 25, 2001
56,570
10,200
126
Wow, a NAS that uses UPnP to automagically open a port from the outside of the router? That sounds like a dangerous idea to me.
 

Ichinisan

Lifer
Oct 9, 2002
28,298
1,235
136
Wow, a NAS that uses UPnP to automagically open a port from the outside of the router? That sounds like a dangerous idea to me.

Yeah. It does require authentication, but I'm not sure how secure the NAS' software is. There may be dozens of vulnerabilities for all I know. It didn't just open HTTP port 80. It also "automagically" opened a bunch of other ports too:

  • 20
  • 21 (FTP)
  • 22
  • 80 (HTTP)
  • 443 (HTTPS)
  • 50000
  • 50001


It's a Seagate FreeAgent GoFlex Home 2TB. Got it for a steal ($40) at the clearance section of my local Target. Believe-it-or-not, I visited that Target clearance section and passed on it a few times before I finally bought it. At first, I wasn't sure if it the deal was good enough. I believe this was *after* the floods in Taiwan caused HDD prices to skyrocket...but I wasn't aware at the time.