The Realtek RTL8211D-VB-GR is a single-port Gigabit Ethernet PHY transceiver designed for use in Ethernet switches, routers, and network-attached storage devices. It supports both 1000Base-T and 100Base-TX, as well as Auto-Negotiation and low-power consumption. The RTL8211D-VB-GR includes support for Wake-on-LAN, Reverse Auto-sensing, and flexible jumbo frame sizes. It also supports Cool Ethernet, which allows the system to reduce power consumption and heat by adjusting the rate of data transmission. The RTL8211D-VB-GR is capable of operating at temperatures up to 105°C and has a built-in temperature sensor for thermal management. It supports data rate up to 2.5 Gbps and is compliant with IEEE802.3 and Energy Efficient Ethernet (EEE).