iptables forwarding script, basic and working

forward

#!/bin/bash
if [ $UID != 0 ]; then echo "Please run as root"; exit 1; fi
SUBNET_ADDRESS='10.0.0.1'
SUBNET_RANGE='10.0.0.2,10.0.0.100,12h'
INTERNET="eno1" #upstream
SUBNET="enp7s0f0" #downstream

ifconfig "$SUBNET" "$SUBNET_ADDRESS" #set your ip for downstream
#ip addr add "$SUBNET_ADDRESS" dev "$SUBNET"

dnsmasq --interface="$SUBNET" --except-interface=lo --bind-interfaces --dhcp-range="$SUBNET_RANGE" #host a lil dhcp guy

echo 1 > /proc/sys/net/ipv4/ip_forward
iptables -A FORWARD -i "$SUBNET" -o "$INTERNET" -j ACCEPT
iptables -A FORWARD -i "$INTERNET" -o "$SUBNET" -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -t nat -A POSTROUTING -o "$INTERNET" -j MASQUERADE