SABnzbd opening UDP ports via UPNP (Fritzbox)

[homi79]

Hello,

i just found out that SABnzbd is opening an UDP-port via UPNP directly after start up on my Fritzbox.
In my case it is UDP 56973.
But when i first saw it yesterday SABnzbd had already opened several UDP ports. I use it for 3 or 4 days now.
Is this normal behavior ?
What is the purpose of these opened ports? I couldn't find anything by searching the web.

Kind regards.

[sander]

Hello,

i just found out that SABnzbd is opening an UDP-port via UPNP directly after start up

What makes you think SABnzbd is opening an UDP-port via UPnP?

In my case it is UDP 56973.

And what is running on UDP port 56973? Probably not SABnzbd, so what would be the use for SABnzbd?

[homi79]

What makes you think SABnzbd is opening an UDP-port via UPnP?

because i tried to find out which application opens the port. So i deleted all UPNP opended ports
on my router. The port reopens via UPNP on the router right after! i start SABnzbd. I can definitely reproduce this behavior.

And what is running on UDP port 56973? Probably not SABnzbd, so what would be the use for SABnzbd?

So you can say for sure, that sabnzbd is not the source of this behavior? I just want to be sure that this behavior is
not normal.. so i know i have to search a little bit more in detail maybe with Wireshark.

[sander]

SABnzbd has no code for UPnP and SABnzbd does not use UDP.

You could find out which process is listening on port 56973. You can do that with "netstat"

On which operating system are you running SABnzbd?

Linux:

Code: Select all

netstat -apon | grep -i -e "listen "

Windows

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netstat -aon | find /i "listening"
tasklist | find /i "<process id>"

Does that show the process on port 56973?

[homi79]

Ok thank you for your help. I will research it in more detail when i am at home at my computer.
OS is Win7

[sander]

OS is Win7

Here's how to find the name of the process listening on UDP port 49153 on Windows (tested on Windows 8 ):

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C:\Users\Sander>netstat -aon | find "UDP" | find "49153"
  UDP    [::]:49153             *:*                                    1488

C:\Users\Sander>tasklist | find /i "1488"
mDNSResponder.exe             1488 Services                   0      4 140 K

So: UDP port 49153 <-> Process ID 1488 <-> mDNSResponder.exe

EDIT & PS:

If you run CMD as admin, you can use

Code: Select all

netstat -abon

which will automagically show the name of the binary involved. Alas the binary name is on the next line, so you can't use FIND:

Code: Select all

  UDP    [::]:49153             *:*                                    1488
 [mDNSResponder.exe]

[homi79]

Thank you for your help. I found out that the "opener" was the IP-help-service of Win7.
Strangely it reopens the port via UPNP right after i start sabnzbd.

[sander]

Thank you for your help. I found out that the "opener" was the IP-help-service of Win7.
Strangely it reopens the port via UPNP right after i start sabnzbd.

Have you set SABnzbd's Logging to +Debug?

[homi79]

At the Commandline? no..