假设loopback接口在其网络中始终是单独的，那么 IPv4 子网前缀比/32这些接口短的实际原因是什么？

此外，为什么根据各种标准 IPv4 环回地址是来自127.0.0.0/8网络的任何地址？不是浪费了大约1600万个IP地址吗？

https://www.rfc-editor.org/rfc/rfc3330

   127.0.0.0/8 - This block is assigned for use as the Internet host
   loopback address.  A datagram sent by a higher level protocol to an
   address anywhere within this block should loop back inside the host.
   This is ordinarily implemented using only 127.0.0.1/32 for loopback,
   but no addresses within this block should ever appear on any network
   anywhere

::1/128有趣的是，用作环回的 IPv6 环回地址没有这样的杂物。

https://www.rfc-editor.org/rfc/rfc4291

   The unicast address 0:0:0:0:0:0:0:1 is called the loopback address.
   It may be used by a node to send an IPv6 packet to itself.  It must
   not be assigned to any physical interface.  It is treated as having
   Link-Local scope, and may be thought of as the Link-Local unicast
   address of a virtual interface (typically called the "loopback
   interface") to an imaginary link that goes nowhere.