If your RD9700 adapter is older than ~2018, consider replacing it with a (e.g., Realtek RTL8153) for better Windows 11 compatibility and speed. However, the steps above will get your RD9700 working for basic 100Mbps use.
A: Disable IPv6 on the adapter (Settings → Network & Internet → Ethernet → Properties → Uncheck Internet Protocol Version 6). If your RD9700 adapter is older than ~2018,
: Offers a database specifically for resolving Corechip device issues on Windows 11. consider replacing it with a (e.g.