Bug#295731: ssh fails to bind link-scope IPv6 addresses

[Hendrik Sattler <debian@hendrik-sattler.de>]

Am Sonntag 10 Dezember 2006 22:55 schrieb Rémi Denis-Courmont:
> Le jeudi 17 février 2005 19:35, vous avez écrit :
> > I try to setup IPv6 on my local network. Ping6 already works but sshd
> > refuses to cooperate:
>
> (...)
>
> > debug1: Bind to port 22 on fe80::2xx:xxff:fexx:xxxx.
>
> You must *ALWAYS* specify the interface ("scope ID" in IPv6 terminology)
> when using link-local addresses. SSH handles them fine, for instance:
>
> On the server side:
> ListenAddress fe80::2xx:xxff:fexx:xxxx%eth0
>
> On the client side:
> $ ssh fe80::2xx:xxff:fexx:xxxx%eth1
>
> This assumes the bind address belongs to eth0 on the server, and the
> client is attached to the server via its eth1 interface.
>
> It works fine for me, I think this bug should be closed.

Where did you get that syntax from?
Why do I have to specify the interface if only one such link-local address 
exists on the system? Or is it just a dumb linux kernel?
If it exists on more than one interface, why can't it then bind to all 
interfaces that this address is valid on?
And again: where is this documented?

HS