Detect IP and port of FAILED outbound requests

Hi all,

We have a managed firewall(Forticlient device if that's relevant) with some quite tight restrictions on outbound connections. The problem is we also need to access a number of sites via customer provided VPN's and or Remote Access software. Frequently these aren't let through the firewall but we can't always see the configuration of where they are trying to go.

Now we can have specific rules added to the firewall to allow them out, but I'm trying to find a tool that can identify outbound requests from my laptop. There's quite a few that can give me the connections that are open at any given time, but I'm after something that somehow captures the intended destination of requests that are failing.

Does such a tool exist, or is my only option the Firewall logs themselves(Which I don't have direct access to so would require continual (paid) calls to the firewall provider)?

Sorry if this is a stupid question - networking is not really my area of expertise.

Thanks