By default, only tests which can execute on any target
will be built. These therefore do not actually use external
network interfaces (though they may configure and initialize
them) but are limited to testing via the loopback
interface.
ping_lo_test - ping test of the loopback address
tcp_lo_select - simple test of select with TCP via loopback
tcp_lo_test - trivial TCP test via loopback
udp_lo_test - trivial UDP test via loopback
multi_lo_select - test of multiple select() calls simultaneously