As @mohammed said in his comment, you should have a look at static routing.
Let's suppose the router A (192.168.0.0) wants to communicate with the network behind the router B (192.168.2.0).
Using static routing, you'll simply add an entry in the routing table on the router A to tell "if I have a packet for network 192.168.2.0, I'll send it to the router ...
If you're looking to merge the networks, why keep them split? Otherwise some systems that use broadcast discovery (like spotify, chromecast, apple play, etc) won't work between those networks.
I'd recommend just making the dlink an access point on your vilfo router, if you want some services to use direct internet calls, vilfo has documentation on split-...
Your first line:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 192.168.8.254 192.168.8.166 35
lists the default route. The default matches any route that isn't matched by any more specific route. So when you ping 10.7.0.1, the PC looks for the best (longest) route to that destination. ...
IP routing works with... IP, not DNS
Best you can do is script something that resolve the hostname to its IP and inject/refresh the IP in the route table. (that's what new generation firewalls that allow FQDN routing does)
Since you didn't specify a topology in the server config file, Openvpn works in net30 mode, which is the default. In this mode, every client will be assigned an IP from a /30 subnet, the other usable IP in the subnet will be allocated for the p2p address of that tunnel. The parameters of the ifconfig and route commands in this mode are "local-ip peer-ip&...
I think in your case you can use Dynamic prefix forwarding, my example of rule in /etc/config/firewall:
option name 'HTTP-SSH-IPv6-myserver01'
option src 'wan'
option proto 'tcp'
option dest 'lan'
option dest_ip '::2c18:81a2:3422:f690/-64'
option dest_port '22 80 443'
option family 'ipv6'
option target 'ACCEPT'
This is possible with iptables NAT masquerading.
Use two linux machines, on subnet 18.104.22.168/24.
ips .10 to .49 routed through 22.214.171.124 (use iptables and nat table masquerade)
ips .51 to .89 routed through 126.96.36.199 (use iptables and nat table masquerade)
If you are using dnsmasq, DO NOT activate DHCP.