I have a remote PRTG QoS (round trip) probe which I imagine was created to run between edge devices
The problem is that I need to use it between devices that sit behind firewalls, and these firewalls NAT outgoing traffic
My PRTG Network Monitor isn't receiving any responses
I have checked firewall and NAT rules and both seem properly configured
NMAP can detect the remote probe if I specify the following options
-sU -p 50000 -g 50000
I therefore assume that the probe wants to respond to me over UDP port 50000
The problem is that, I presume because of NAT, my packets don't have a source UDP port of 50000
Is there a way to ensure that the source port of an outgoing packet is preserved ?
We have Cisco ASA 5505 router at our end and the datacenter has a (Debian) Vyatta firewall
Any ideas ?