100.64.65.66 is a Special Purpose IP Address.

100.64.0.0/10 - Shared Address Space
100.64.0.0/10 was allocated on April of 2012.

Addresses in 100.64.0.0/10 may be used as the source address of an IP datagram that transits two devices.

Addresses in 100.64.0.0/10 may be used as the destination address of an IP datagram that transits two devices.

Addresses in 100.64.0.0/10 are forwardable.
A router may forward an IP datagram to Addresses in 100.64.0.0/10 between external interfaces

Addresses in 100.64.0.0/10 are NOT globally reachable
An IP datagram may NOT be forwarded to Addresses in 100.64.0.0/10 beyond a specified administative domain.

The 100.64.0.0/10 Address block is reserved to be used as Shared Address Space to accomodate the need of Carrier-Grade NAT (CGN) devices. It is anticipated that Service Providers will use this Shared Address Space to number the interfaces that connect CGN devices to Customer Premises Equipment (CPE).

[ RFC6598, ^ ] , Address Allocation for Private Internets

  
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