De ip-address(8)
:
It is possible to have several different addresses attached to one device. These addresses are not discriminated, so that the term alias is not quite appropriate for them and we do not use it in this document.
Você pode, no entanto, emular a funcionalidade "alias" suspensa usando rótulos:
$ ip address add dev eth7 42.42.42.42/23 label eth7:foo