> An interface on linux has only one ip address. absolutely not true. Neither for IPv4 nor IPv6, where it's even the default to have a multitude of addresses o

> An interface on linux has only one ip address. absolutely not true. Neither for IPv4 nor IPv6, where it's even the default to have a multitude of addresses on an interface. > The "localhost" interface will either designate the ipv4 127.0.0.1 interface or the ipv6 ::1 interface. That's the realm of undefined behavior and system specifics. no it won't. My loopback (lo) interface has both 127.0.0.1 and ::1 as its addresses.