@tekbird

It's under Firewall->Access Control option.

For example:

https://www.tp-link.com/us/support/faq/2026/

  @Somnus thank you for the reply. I am trying to limit access between internal machines, not external to internal and portforwarding.

  @tekbird

It should be the same, the Interface face choose LAN, and then put in your source IP and destination IP.

I'm not using standalone mode now, but I can show you on the controller it's easy to choose the LAN and IP group.

  @Somnus I have the IPs as below:

And my IP Group as below (which is just a one to one mapping with IP address):

But when I go to create access rules and select Lan->Lan, I can't select the IPs (instead it asks me to select network):

  @tekbird 

Try the Omada Controller, you won't regret it. Many features are only available with the Controller.

  @Somnus is that a paid service? do i have those features avaiable in this web ui i shared? if you are asking me to pay again, not a real solution for us.

  @tekbird 

Oh no need to pay anything. Omada Softwre Controller is free to download and use.