Major Description
On Ubuntu, it seems like we sometimes end up with connections from 127.0.1.1 to 127.0.0.1 when running a local cluster and connecting to to it from the same machine. This is because Ubuntu puts an entry with the host's external hostname in /etc/hosts as 127.0.1.1, and the tablet server ends up registering with that name. The code that detects loopback connections sees the "127.0.0.1 -> 127.0.1.1" and decides it's not loopback.