external inter-VLAN L3 switching / routing

[Tubs]

Hello,

currently my home network with a hand full of VLAN is set-up with in that way that opnsense is doing all routing between the sub-nets. All devices are connected to one L2 switch. But since I upgraded a part of my home network to 10 Gbit, I now have a bottleneck between the networks I call "LAN" and "DMZ". My opnsense is a small box with 1 GBit ports only, but good enough to handle the traffic to and from internet.

Three goals I have:
(1) I would like to move the routing between the network "LAN" and "WAN" to an external 10 GBit L3 switch (Ruckus 7250). For all other networks the routing can stay on the opnsense box. Only few traffic needs to get routed that is related to those.
(2) I would like to utilise the available 3 physical ports (A2, A3, A3) on the opnsense box as much as possible.
(3) I would like to minimize the overhead on the opnsense box generated by VLAN tagging or LAGG.

My ideas are:
- run LAGG over all three ports and run one VLAN trunk to the switch with all networks in
- run one VLAN / VLAN trunk on each of the three ports and manually distribute the VLAN / subnets acc. expected traffic
- as shown on the sketch: one separate gateway and route for LAN and DMZ, directly connected without VLAN or LAGG. All other packed in one VLAN trunk. No need for LAG or VLAN on the networks with highest traffic.

Any disadvantages by going with the last one?
Better ideas?

Code: [Select]

  opnsense                               L3 switch

       A1 --------X WAN

                GW1 - 192.168.1.10/30
       A2 -------------------------------- B1 - LAN: 192.168.40.0/24   

                GW2 - 192.168.1.20/30
       A3 -------------------------------- B2 - DMZ: 192.168.50.0/24

                 VLAN trunk
       A4 -------------------------------- B3 |--- VLAN 10: 192.168.10.0/24
                                              |--- VLAN 20: 192.168.20.0/24
                                              |--- VLAN 30: 192.168.30.0/24

[Tubs]

Nobody, who can give me a hint if this network topology is correct?

I do not look for detailed configuration help. I only want to know if this way of routing will work and if it is the best way to do so.

[Tubs]

It looks like I was thinking too complex.

After further research I found out, that in my small network I could do it much more simple: no transport net and therefore OPNsense firewall and L3 switch directly connected to the two networks I would like to route in between by L3 switch. Default route to firewall and L3 switch as gateway for for hosts in DMZ and LAN network.