iptables.up.rules

*filter

# http://articles.slicehost.com/2010/4/30/ubuntu-lucid-setup-part-1

#  Allows all loopback (lo0) traffic and drop all traffic to 127/8 that doesn't use lo0
-A INPUT -i lo -j ACCEPT
-A INPUT ! -i lo -d 127.0.0.0/8 -j REJECT

#  Accepts all established inbound connections
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

#  Allows all outbound traffic
#  You can modify this to only allow certain traffic
-A OUTPUT -j ACCEPT

# Allows HTTP and HTTPS connections from anywhere (the normal ports for websites)
-A INPUT -p tcp --dport 80 -j ACCEPT
-A INPUT -p tcp --dport 443 -j ACCEPT

#  Allows SSH connections (only 4 attempts by an IP every 3 minutes, drop the rest to prevent SSH attacks)
-A INPUT -p tcp -m tcp --dport 22 -m state --state NEW -m recent --set --name DEFAULT --rsource
-A INPUT -p tcp -m tcp --dport 22 -m state --state NEW -m recent --update --seconds 180 --hitcount 4 --name DEFAULT --rsource -j DROP
-A INPUT -p tcp -m state --state NEW --dport 22 -j ACCEPT

# Allow ping
-A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT

# log iptables denied calls
-A INPUT -m limit --limit 5/min -j LOG --log-prefix "iptables denied: " --log-level 7

# Reject all other inbound - default deny unless explicitly allowed policy
-A INPUT -j REJECT
-A FORWARD -j REJECT

COMMIT

iptables2.up.rules

*filter

# Since v1 I have improved it some (10/3/2012)
# http://articles.slicehost.com/2010/4/30/ubuntu-lucid-setup-part-1

#  Allows all loopback (lo0) traffic and drop all traffic to 127/8 that doesn't use lo0
-A INPUT -i lo -j ACCEPT
-A INPUT ! -i lo -d 127.0.0.0/8 -j REJECT

#  Accepts all established inbound connections
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

#  Allows all outbound traffic
#  You can modify this to only allow certain traffic
-A OUTPUT -j ACCEPT

# Allows HTTP and HTTPS connections from anywhere (the normal ports for websites)
-A INPUT -p tcp --dport 80 -j ACCEPT
-A INPUT -p tcp --dport 443 -j ACCEPT

# UN-COMMENT THESE IF YOU USE INCOMING MAIL!

# Allows POP (and SSL-POP)
#-A INPUT -p tcp --dport 110 -j ACCEPT
#-A INPUT -p tcp --dport 995 -j ACCEPT

# SMTP (and SSMTP)
#-A INPUT -p tcp --dport 25 -j ACCEPT
#-A INPUT -p tcp --dport 465 -j ACCEPT

# IMAP (and IMAPS)
#-A INPUT -p tcp --dport 143 -j ACCEPT
#-A INPUT -p tcp --dport 993 -j ACCEPT

#  Allows SSH connections (only 3 attempts by an IP every 2 minutes, drop the rest to prevent SSH attacks)
-A INPUT -p tcp -m tcp --dport 22 -m state --state NEW -m recent --set --name DEFAULT --rsource
-A INPUT -p tcp -m tcp --dport 22 -m state --state NEW -m recent --update --seconds 120 --hitcount 3 --name DEFAULT --rsource -j DROP
-A INPUT -p tcp -m state --state NEW --dport 22 -j ACCEPT

# Allow ping
-A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT

# log iptables denied calls (Can grow log files fast!)
#-A INPUT -m limit --limit 5/min -j LOG --log-prefix "iptables denied: " --log-level 7

# Reject all other inbound - default deny unless explicitly allowed policy
#-A INPUT -j REJECT
#-A FORWARD -j REJECT

# It's safer to just DROP the packet
-A INPUT -j DROP
-A FORWARD -j DROP

COMMIT