You mentioned in a comment that you use ifconfig to bring the interface up. In this case, your problem is that ifconfig does not use the
interfaces file (it only tells the interface to start receiving packets). This configuration file is specific to Debian/Ubuntu and is only read by the ifupdown tools
ifdown. So you would have to use:
Even then, your configuration will be rejected because the configuration file syntax uses "
iface", not "
interface", to denote a new logical interface. (See the interfaces(5) manual for full syntax description.)
pre-up line is also 1) unnecessary: it's done automatically, and 2) mistyped: it's "
fe80::a00:27ff:fe1e:5edf address is shown not because of any configuration, but because IPv6 requires it. Every interface is required to have a link-local address based on the "interface ID" (its MAC address); these addresses are added automatically by the Linux kernel.
(Remember that an interface can have many addresses. You can have both
fe80::a00:27ff:fe1e:5edf on the same interface, and it will still work.)
Also remember that the
fe80::/10 addresses are link-local – in other words, they are never routed, and the
gateway configuration setting is meaningless.
This means that whenever you try to access a link-local address, you must manually specify the interface to use – this is done by adding a zone index to the address. (On Linux, the zone index is the same as interface name.) For example, to connect over eth0, you have to add
(Oliver Salzburg's answer is also correct – you must not specify a subnet mask when referring to a single host.)