Can you advice what model could do the trick? I assume that no integrated option is available for that? Interim solution could be to have dummy switch on fron but I would like to avoid that.

  @Lantti 

I am bit new on this area but decided to take challenge. I have ISP providing 1x RJ-45 for WAN. I bought ER7212PC to route forward from there. I would need to set up 1x LAN port that is bridged to WAN to "pass through" connection. And then all the rest LAN ports of the device would be behind NAT in their own network.

Aa @Clive_A says, its not possible to do that.

Perhaps if you explained what you are trying to achieve, then other may be able to advise how that might be otherwise done.

  @Lantti 

The EV charging router cannot be behind NAT as they told me, double NAT is not the good practice

Yes double NAT is not ideal, but will probably work fine.

Insisting on a direct internet connection by the supplier is VERY restrictive and I suspect in practice not necessary. Most of these systems make outgoing connections to a server and so will work fine even with double NAT.

I suggest you try it and see if it works. Make sure that the ER605 LAN subnet is different to that of the EV router. I suggest changing it to something obscure like 192.168.14.1.

The EV router is likely to be 192.168.0.x or 1.x but if you can check what it actually is then all the better ?

I'm assuming that the EV router WAN is configured for DHCP, so If it doesnt work straight away then add the EV router into the DMZ on the ER605.

Use VLAN's on the ER605 to segregate the EV router and the rest of the network