```
# Edit /etc/NetworkManager/NetworkManager.conf adding the following
# to make network manager stop managing your ethernet interface
[keyfile]
unmanaged-devices=mac:3c:90:01:39:b2:62;
# Use the MAC address from your ethernet card
# You can get the MAC address with the command:
ip link show dev eth0
# (assuming your ethernet device is called eth0)

# restart network-manager to pick up the changes
sudo service network-manager restart

# Install dnsmasq
sudo apt install dnsmasq

# Add the following line to /etc/dnsmasq.conf
dhcp-range=172.23.0.50,172.23.0.200,12h

# Run the following to turn you computer into a gateway
# (replace eth0 with your ethernet interface name)
# (replace wlan0 with your wifi interface name)

ifconfig eth0 172.23.0.1 netmask 255.255.255.0 up
echo "1" > /proc/sys/net/ipv4/ip_forward
iptables -P FORWARD ACCEPT
iptables -t nat -F POSTROUTING
iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE
/etc/init.d/dnsmasq restart

# Connect another computer to your ethernet port and it should get an IP using DHCP and have internet access
```