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Hi<br />
<br />
I have a remote PRTG QoS (round trip) probe which I imagine was created to run between edge devices<br />
The problem is that I need to use it between devices that sit behind firewalls, and these firewalls NAT outgoing traffic<br />
<br />
My PRTG Network Monitor isn't receiving any responses &nbsp;<br />
I have checked firewall and NAT rules and both seem &nbsp;properly configured<br />
NMAP can detect the remote probe if I specify the following options<br />

<blockquote>
-sU -p 50000 -g 50000
</blockquote>
I therefore assume that the probe wants to respond to me over UDP port 50000<br />
<br />
The problem is that, I presume because of NAT, my packets don't have a source UDP port of 50000<br />
<br />
Is there a way to ensure that the source port of an outgoing packet is preserved ?<br />
We have Cisco ASA 5505 router at our end and the datacenter has a (Debian) Vyatta firewall <br />
<br />
Any ideas ?<br />
thanks<br />
yann
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Hi

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 ?
thanks
yann

Preserve source port through NAT

Cisco PIX is a dedicated hardware firewall appliance; the Cisco Adaptive Security Appliance (ASA) is a firewall and anti-malware security appliance that provides unified threat management and protection the PIX does not. Other Cisco devices and systems include routers, switches, storage networking, wireless and the software and hardware for PIX Firewall Manager (PFM), PIX Device Manager (PDM) and Adaptive Security Device Manager (ASDM).

Cisco

A router is a networking device that forwards data packets between computer networks. Routers perform the "traffic directing" functions on the Internet. The most familiar type of routers are home and small office cable or DSL routers that simply pass data, such as web pages, email, IM, and videos between computers and the Internet. More sophisticated routers, such as enterprise routers, connect large business or ISP networks up to the powerful core routers that forward data at high speed along the optical fiber lines of the Internet backbone. Though routers are typically dedicated hardware devices, use of software-based routers has grown increasingly common.

Routers

Software firewalls, also known as host-based firewalls, provide a layer of software on one host that controls network traffic in and out of that single machine. Most operating systems now include firewall software, but many available software firewalls include central distribution, antivirus systems and disaster recovery.