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Special-Use Addresses
Several address ranges are reserved for "Special Use". These addresses all have restrictions of some sort placed on their use, and in general should not appear in normal use on the public Internet. The following briefly documents these addresses – in general they are used in specialized technical contexts. They are described in more detail in RFC 3330.
"Private Use" IP addresses:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
The above address blocks are reserved for use on private networks, and should never appear in the public Internet. There are hundreds of thousands of such private networks (for example home firewalls sometimes make use of them). The IANA has no record of who uses these address blocks. Anyone may use these address blocks within their own network without any prior notification to IANA.
The point of private address space is to allow many organizations in different places to use the same addresses, and as long as these disconnected or self-contained islands of IP-speaking computers (private intranets) are not connected, there is no problem. If you see an apparent attack, or spam, coming from one of these address ranges, then either it is coming from your local environment, or the address has been "spoofed".
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(from:
http://www.iana.org/faqs/abuse-faq.htm#StructureofIPAddresses)
So this is very strage but still, i think u can ban "whole" 172.0.0.1 without setting the porty so then all the ports for that ip will be banned.
Please correct me if i am wrong.