What else do you have on the ex2200?
The configuration you have will put these four ports into your current switch default vlan which is likely and internal one.
I assume you want to isolate these four ports from all the internal vlans. So you have two options:
option 1 - layer 2 only vlan
Create a new vlan with an unused vlan tag value to assign to all four ports.
Make sure there are no layer 3 interfaces in this vlan so they cannot communicate with anything else
I doubt you need to worry about loops on these ports to the upstream routers or firewalls so the rstp is probably not needed
option 2 - isolated routing instance
This will create more separation and guarantee no access to internal vlans
Create a virtual router routing instance
Assign all 4 ports to this routing instance
The configuration you posted as just ethernet switching without need for vlans will work