Change the NAT loopback configuration
Change the NAT loopback configuration
Your setup has switched from an unmanaged to a managed TP-Link switch, which can affect how NAT functions. This change might have disrupted the NAT loopback behavior you were expecting.
Unless you've set up specific Layer 3 rules, Loopback should be a router problem. Have you attempted reinstalling the old switch and checked if Loopback functions properly now?
I left the settings mostly unchanged. I haven’t altered anything else; this is the sole network adjustment I’ve made. The modem and router remain the same, but they’re now connected to a different coaxial port.
Is NAT loopback necessary? It's usually discouraged because it acts like a shortcut and uses CPU resources that could be better used for real internet traffic. Instead of relying on it, consider using a local DNS override to skip the router for LAN-to-LAN communication.
It varies by device; some routers allow adjustments there while others don't. If that's the case, you'll have to handle it in Windows instead. The issue becomes more complex if you rely on a phone or tablet, since those platforms typically lack direct support—you'd need router capabilities or a solution like a Pi-Hole to manage DNS independently.