What are the three IPv4 private address ranges defined in RFC 1918, and what is the key characteristic that makes them suitable for internal network use?

• A.RFC 1918 private ranges: 10.0.0.0/8 (16,777,216 addresses), 172.16.0.0/12 (1,048,576 addresses, covers 172.16.0.0 - 172.31.255.255), 192.168.0.0/16 (65,536 addresses). Key characteristic: these ranges are not routed on the internet; any router on the public internet receiving a packet with a private source/destination IP drops it, making the ranges reusable by any organization without IANA registration
• B.RFC 1918 addresses: 10.0.0.0/8, 172.0.0.0/8, 192.168.0.0/8. These ranges are encrypted automatically by all routers
• C.RFC 1918 private ranges are globally unique but free to use; they are registered in a global database by each organization
• D.RFC 1918 defines only one private range: 192.168.0.0/16; the 10.x.x.x and 172.x.x.x ranges are for ISP use only