[Bloat] ipv6 fe80:: addresses, vlans and bridges... borked?

[Roland Bless]

Hi Dave,

On 11.05.2011 05:32, Dave Taht wrote:
> 1) in a wireshark analysis, the %interface part is lost

But your wireshark is listening on some specific interface,
isn't it? This interface is your context then and link locals are
unique on that particular link (which is assured by
Duplicate Address Detection). Are you facing the problem from the
switch's perspective (e.g., that you can determine the receiving
i/f from the destination address of received packets) or from another
another device's perspective?

> 2) we have 2^64 possible choices for fe80 addresses. I don't see what
> having them all be the same buys me.

You can assign an individual fe80:: address to an interface, e.g.,
fe80::b101 for bridge one interface 1,  fe80::b102 bridge one
interface 2 etc. if that helps. But be aware that it may create
address collisions in case you have two such bridges on the same
link :-( Therefore, using (modified) EUI-64 addresses within the
64-bit seems to be a good choice.

> 3) It worries me in the babel routing protocol

Sorry, I didn't study the spec so far. What is the
particular problem there? Maybe there is a problem
with the assumptions in the protocol.

> 4) My bridges are misbehaving over ipv6 in the general case and I'm
> willing to grasp at straws.

What is that misbehavior? That a bridge is using the same link local
address on each of its links? That's ok as long as its unique on that
particular on-link subnet.

Regards,
 Roland