127.0.0.0 is in the 127.0.0.0/8 block which is assigned as the Internet host loopback address. A datagram sent by a higher-level protocol to an addreess anywhere within this block loops back inside the host. This is ordinarily implemented using only 127.0.0.1 for loopback. Addresses within the entire 127.0.0.0/8 block do not legitimately appear on any network anywhere.
[ RFC1122, Section 3.2.1.3 ]

            ()      ()
           (  )____(  )
          || __    __ ||
       (|||  \_\  /_/  |||)
          ||          ||
           /          \
           \   ____   /
            \  \__/  /
            /\______/\
         \\/IPDUHHUDPI\//