[ubuntu] Losing Internet

When ever I try to run this I lose internet access

iptables -A FORWARD -o wlp3s0 -i vboxnet0 -s 192.168.56.0/24 -m conntrack --ctstate NEW -j ACCEPT
iptables -A FORWARD -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
iptables -A POSTROUTING -t nat -j MASQUERADE
echo 1 > /proc/sys/net/ipv4/ip_forward