sudo iptables -L
Chain INPUT (policy DROP)
target     prot opt source               destination
ACCEPT     all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere             ctstate RELATED,ESTABLISHED
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:http

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination




nano /etc/iptables/rules.v4
# Generated by iptables-save v1.4.21 on Wed May  4 23:53:23 2016
*filter
:INPUT DROP [469:58510]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [1788:276430]
-A INPUT -i lo -j ACCEPT
-A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
COMMIT
# Completed on Wed May  4 23:53:23 2016