[K12OSN] How do I stop attempted logins

[Dr. Daniel Loomis]

Thanks for the advice.  I have added the following rules to
/etc/sysconfig/iptables to slow down the Asian hordes:

-A INPUT -s 200.0.0.0/8 -j DROP
-A INPUT -s 202.0.0.0/8 -j DROP
-A INPUT -s 210.0.0.0/8 -j DROP
-A INPUT -s 211.0.0.0/8 -j DROP
-A INPUT -s 212.0.0.0/8 -j DROP
-A INPUT -s 221.0.0.0/8 -j DROP
-A INPUT -s 222.0.0.0/8 -j DROP

My Doctorate is in Theology, not computer science, so I have only
passing acquaintance with subnetting rules.  However, if I understand
correctly, it seems I could replace the above with a single rule like
the following:

-A INPUT -s 200.0.0.0/2 -j DROP

Would the above rule block all subnets in the range 200.0.0.0 to
255.0.0.0 or is there another way to declare the whole subnet?

Daniel