Netowork topology advise - describe the correct way of connecting RB450Gx4 and CRS109-8G-1S-2HnD

RouterOS Beginner Basics
1

Hi,

I am faced with the challenge of doing the network for a small company with two offices. I do hove some idea how to get the job done but I am looking for advise mostly around the CRS device as a router switch combination is still a mystery to me.

Here is the current architecture:

Site A Site B
Mikrotik CHR <---- EoIP+IPSEC ----> CRS109 ----> (around 20 L3 VLANs some of them in bridges with other interfaces) —> Server farm which untags the VLANs and uses them in bridges for VMs

This worked for a while, however the CRS CPU is too weak for serious traffic via IPSEC so we decided to put a RB450Gx4 in front of it in the following architecture:

Site A Site B
CHR <---- EoIP+IPSEC ----> RB450Gx4 ----> CRS109 ----> (around 20 L3 VLANs some of them in bridges with other interfaces) —> Server farm which untags the VLANs and uses them in bridges for VMs

And here are my questions:

  1. Currently the CRS handles all addressing/firewalling and DNS for the client devices, is it a good idea to offload that to the RB450Gx4?
  • How do you usually do that with Wi-Fi involved as well?
  1. I am planing to use L2 VLANs and present those from the RB devices all the way to the server farm, will I be able to even do that on a RB device?
  • How can I do IP addressing in the L2 VLANs on a RB device (currently it is not possible to do it on the CRS, that is why we use L3 VLANs)?
  1. What are the requirements for using FastPath on CRS?
  2. Would you connect those devices differently, use different typologies?

I can draw more detailed diagram if needed.

Thanks!