LAN segment sandbox

[banksiaboy]

This is a rephrase of my previous question. I'm not sure how to ask. Newbie

On proxmox I have a test bridge with a nic. The bridge is assigned on OPN.  OPN in vm on Proxmox. OPN has its WAN to my local network. Can I set up the same network segment addressing on this bridge as in my local lan, but isolated from it. I need to sandbox some misbehaving devices as if on my local lan. Need access to internet from bridge through OPN WAN.

How should I do this?

Thanks

[banksiaboy]

Is this a stupid question? Is there some other way I should be looking at this? I'm just trying to set ip my network  anew  and learn a few things but I can't get started because the Omada SDN controller is knocking my iPhone off the network, so I need to isolate it. I don't know how to do that. I would really like some help.

[banksiaboy]

Well it must have been a stupid question. Not one reply

[cookiemonster]

Probably holidays have people not looking as much at the forum.
I'm not entirely clear what you mean.
I _think_ you say your OPN VM has two interfaces in Proxmox and the WAN is in the same segment as your current  LAN, so OPN WAN is a private ip like 192.168.1.50 for the sake of understanding.
But you also want the LAN of OPN to be in the same LAN and therefore get an ip in the same segment i.e. 192.168.1.60 and put some devices on downstream from this LAN. If this is what you want just for the purpose of making OPN be a sort of "gate", then you can'tc, because of the LAN segment is the same one.
If I am misunderstanding your question, please draw a diagram with numbers so I can get the thinking.

p.s. How many NICs do you have on your Proxmox host?