Intervlan for two switches

Howdy, i’m newbie in MT devices.

I’m looking for solution in my situation - topology in attachement.

There is one router CRS125 and two switches CRS354.

On both switches there is VLAN400, it should be routed on R1. And there is a question - how in simple and effective way configure R1 to realize this routing when there is two switches connected ? The VLAN400 should also have own DHCP server.

The second question, if there will be additional VLAN (eg. id 500), but non-routable, is there way to handle traffic on R1 with enabled HW support ?

Thanks in advance !
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