dtc-xen-firewall 0.5.17-1 (s390x binary) in ubuntu yakkety

 If running in a production environment, you might want to have a basic
 firewall running on your dom0 to avoid having DoS attack. This is not the
 state-of-the-art, but just another attempt to make things a bit more smooth.
 Comments and contribution are more than welcome!
 .
 The main principle of this firewall script is to rate limit connections to
 both your dom0 and your VPSes. It's principle is NOT block any connection. For
 example, dtc-xen-firewall denies ssh for 300 seconds after 10 attempts on your
 dom0, rate limit ping to 5 per seconds on your dom0 and to 50/s globally for
 all your VPS, and does the same kind of thing for SYN flood attacks. Take
 care, it also blocks any connection to the port 25, as in a normal dom0, you
 would install a mail server to send system messages to the administrators, but
 you don't want to accept any incoming message.