I am unexpectedly having to upgrade my company's network router/VPN due to the departure of another employee.
My company uses a Sonic Wall network appliance to provide VPN access to our internal network for employees who work from home or are otherwise remote. The network infrastructure was originally set up by a paid contractor (who has not been available for some years), and maintained by an employee who left the company on short notice. This employee was the only one who had the credentials needed to access the Sonic Wall's admin console. There is no way to recover the password other than performing a factory reset. I understand this was a lapse in our operations, and we have taken steps to ensure a similar situation won't occur in the future.
The VPN works and is being used by numerous employees on a daily basis. After some research, I purchased a Synology router to replace both the inaccessible Sonic Wall device and an older WiFi router. We will eventually set up a mesh network to provide full coverage. The Synology device has a VPN Server module that can be installed.
Can I set up the Synology device in such a way so that both it and the Sonic Wall device can provide VPN access at the same time? This would allow me to test the new VPN (and get our employees set up with access), and then once all employees have switched over, I could just connect our switches to the new appliance. My thoughts were that I could accomplish this by setting up some kind of port forwarding on our Comcast cable modem so that the Synology VPN would be accessible on a different port. Is this possible? If so, what do I generally need to change on the Comcast router/modem to enable this?
I have access to the admin panel for the Comcast cable modem. It looks like most of the settings are defaulted, with the exception of the firewall being disabled (presumably the Sonic Wall device also functions as our firewall). The Sonic Wall appliance is the only device directly connected to the modem. A switch connects to the Sonic Wall appliance, and other switches, servers, etc are connected to it.
