iptables
Just some iptables cheatsheet :
show the current iptables:
iptables -L
check firewall service:
service iptables status
enable iptables service:
chkconfig –level 345 iptables on
save iptables
iptables-save
save iptables to /etc/sysconfig/iptables
service iptables save
Ban an IP:
iptables -A INPUT -s a.b.c.d -j DROP
# using a netmask:
iptables -A INPUT -s x.y.z.0/24 -j DROP
To delete a rule:
iptables -D INPUT -s a.b.c.d -j DROP