I have a Draytek 2860 on a customer site with LAN 1 based on 192.168.1.0 network. On that LAN the customer also has a second router which manages a large area WiFi network which uses a 172.16.x.x network address.

The 2nd routers WAN port picks up a DHCP address from the Draytek (192.168.1.x) but uses 172.16.x.x on its LAN side.

My goal is to be able to remotely access the wifi nodes via web browser on the 172.16 network but doing so I'll somehow need to traverse the Draytek.

I know I could create a 2nd LAN for the WIFi network but we have to use the WiFi router due to some of the features it has.

Anyone have any thoughts if this is possible?

Thanks in advance

I would have thought that you'd need to use the Wifi Router's equivalent of "Port Redirection", to open (unique) ports on its WAN side that map through to each of the Wifi Router's LAN client's HTTP port.

something like:-

WAN:81 -> LAN node 1:80
WAN:82 -> LAN node 2:80
WAN:83 -> LAN node 3:80

Of course, if this Wifi Router is any good, it'll have a built-in VPN server - and you could get unfettered access to the 172.16.x.y network that way

The wifi router does have VPN server capabilities. Are you thinking I should fix the IP the WiFi router gets on the Draytek then port forward the VPN traffic to that IP? Would that work?

Fixing the IP address is probably a good thing to do regardless.
Re: VPN...you could only access it via a client on individual PCs. You couldn't (for example) establish any sort of VPN from the vigor-because it will only do that from its WAN port.