This project is a tiny router which routes packets from an enc28j60 ethernet port to the esp8266. The ETH is configured to use DHCP to aquire an ip address from the router which it is plugged into. This is not a NAT router, and as such you will need to configure a default route to network 192.168.4.0 from the router which it is plugged into. Speeds of .42 Mbps down and 0.57 Mbps up were achieved with one device connected to the access point. The esp8266 which was used in this case was the NODEMCU. Thanks to Martin-Ger for writing esp_wifi_repeater, I have borrowed some code from the project and used martin-ger/esp-open-lwip as a base for the LWIP. The ENC is connected to the ESP8266 using SPI. Thanks metalphreak for the SPI driver. To wire the ESP and ENC together use the (taken from Martin-Ger esp_wifi_repeater).
NodeMCU/Wemos ESP8266 ENC28J60
D6 GPIO12 <---> MISO
D7 GPIO13 <---> MOSI
D5 GPIO14 <---> SCLK
D8 GPIO15 <---> CS
D1 GPIO5 <---> INT
D2 GPIO4 <---> RESET
Q3/V33 <---> 3.3V
GND <---> GND
Use a pulldown resistor for GPIO 15 https://esp8266hints.wordpress.com/category/ethernet/.