This library creates standard Arduino Ethernet networking API over ESP8266 or ESP32 AT commands. The Arduino Ethernet networking API was established by Arduino Ethernet library.
EthernetEspAT extends the WiFiEspAT library with Ethernet object and Ethernet named aliases for WiFiClient, WiFiUDP and WiFiServer from WiFiEspAT.
The library is for all Arduino MCU architectures. It enables secure connection (https) over wired network even for 8-bit architecture boards.
Standard AT firmware builds by Espressif don't support Ethernet.
ESP32 AT firmware supports Ethernet commands but they have to be enabled in build configuration and build from sources.
The ESP32 AT firmware official source only supports Ethernet PHY modules: LAN8720, IP101, DP83848 and RTL8201. Here you can download some ESP32 AT firmware binaries with Ethernet support. There is a modified AT firmware supporting W5500 too.
ESP8266 AT firmware by Espressif doesn't support Ethernet. Jiri Bilek's ESP_ATMod firmware for ESP8266 supports Ethernet with Ethernet chips supported by the ESP8266 Arduino platform. Those are W5500, W5100 and ENC28J60.
For installing and testing the AT firmware see the WiFiEspAT documentation.
Photo of a 3.3 V Arduino board with esp8266 Ethernet 'shield' containing a Wemos D1 mini and a Wiznet Wiz850io module.