$ perl -e " $foo = qx{perl -e \x22system q/ping 127.6.6.6 >NUL/\x22} "

$
$ perl -e " $foo = qx{perl -e \x22system q/ping 127.6.6.6 >&NUL/\x22} "
>& was unexpected at this time.

$ perl -e " $foo = qx{perl -e \x22system q/ping 127.6.6.6 &>NUL/\x22} "
The syntax of the command is incorrect.