X4300 Pro & Putty over vpn to work network
I received this reply to my original question
Yes, most services use specific ports for their connections, such as Cisco's Anyconnect VPN server requiring port 443 to be opened. Depending on what VPN service you are using the required ports may be different.
You can see the steps in this guide to manually open a port on your Deco, but I would first recommend seeing if the uPnP setting is enabled or disabled, as this is what most likely made your last router automatically work with the service. You can see where to find the setting in the first screenshots of the FAQ.
Whai i didn't understand and didn't explain very well the first time is that the issue is when I connect to my work VPN from home and then try and access a device on that network via SSH it times out. I can connect to my work VPN and see files etc but I can't SSH into a device.