comp.os.linux.networking

D. Stussy a écrit :
>
> Also, if you don't put the 6to4
> address on the sit0 interface, it does work but the route that gets
> auto-added (for other than a /128) gets added to the wrong interface and the
> auto-lookup for the embedded IPv4 remote tunnel end breaks, unless you also
> manually add "2002::/16" to sit0.

Of course the sit interface must have the 2002::/16 route. I did not say
otherwise. This does not mean that the sit interface must have a 6to4
address or other interfaces must not have 6to4 addresses.

> However, you still need the 2002::/16 route on sit0 for it to work with
> OTHER PEOPLE's 6to4 addresses.

Correct.

> Additionally, you will have at least one
> address for your local host, and it really belongs on sit0

No, it can be assigned to any interface. If the output interface has no
suitable address, the network stack will use a suitable address from
another interface. I.e. if you assigned a 6to4 address only to the LAN
interface, this address can be used for communications on the sit interface.

> = so no reason not to "ifconfig sit0 inet6 add 2002:xxxx:xxxx::1\16"
> where it's supposed to be.

One reason : it is not required when the host already has a 6to4 address
assigned to another interface.
Besides, why assign 2002:xxxx:xxxx::1 and not any other address in your
6to4 prefix such as 2002:xxxx:xxxx::, 2002:xxxx:xxxx::2,
2002:xxxx:xxxx:1234:5678:9abc:dead:beef... ?

> Unlike IPv4, an interface can have multiple IPv6 addresses assigned to
> it.

You mean *like* IPv4. An interface can have multiple IPv4 addresses. Do
not let ifconfig fool you.

$ ip addr show dev eth0
2: eth0: mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:e0:29:04:b6:61 brd ff:ff:ff:ff:ff:ff
inet 192.168.0.1/24 brd 192.168.0.255 scope global eth0
inet 192.168.100.1/24 brd 192.168.0.255 scope global eth0:0
inet6 2001:7a8:6d23:1::1/64 scope global
inet6 2002:d529:ad23:1::1/64 scope global
inet6 fe80::2e0:29ff:fe04:b661/64 scope link