I think I’ve done that. But for clarity:
WAN is just cable internet. That’s it.
Cable modem with 2.5 Gbit connection going to port 1 on the router.
10 Gbit fiber connection to my L3 switch.
LAN is on 192.168.0.0/23 subnet. I also have a number of VLANs that are all in the 10.0.0.0/8 subnet.
The router is at IP 192.168.1.1. The switch has a LAN IP of 192.168.1.198 that is on a routable VLAN.
The goal is to route traffic from the 192.168.0.0/23 subnet to the 10.0.0.0/8 subnet. For devices on the 10.0.0.0 VLANs their gateway is the VLAN IP address on the switch.
Normal routing table goes:
Destination: 10.0.0.0
Mask: 255.0.0.0
Gateway: 192.168.1.198
Just making a normal route entry in the MikroTik resulted in extremely slow performance when trying to get to the 10.0.0.0 VLANs. Brutally slow.
This should be sufficient to describe things.