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

Roland Bless roland.bless at kit.edu
Mon May 9 10:49:03 EDT 2011


Hi Dave,

On 09.05.2011 05:26, Dave Taht wrote:
> I am modestly stumped as to how to solve this properly. I think it's
> been causing problems with ipv6 for a long time, but I could be wrong.
> 
> see http://www.bufferbloat.net/issues/126
> 
> Basically although the underlying interfaces do have unique mac
> addresses (for some reason the underlying eth0 interface is sharing a
> mac address with the wlan0 interface??),
> the bridged to a vlan fe80:: addresses are all the same. This strikes me
> as a problem.

It seems that in these cases the ether/link address is also the same,
therefore the interfaces configure all the same link-local address.
Link local addresses are only unique with respect to their link,
i.e., usually you have to specify the interface in addition to the
fe80::/64 destination address, e.g., ping6 fe80::c63d:c7ff:fe8b:6e1a%vlan1

> Is there a standard for renaming fe80:: addresses to represent they are
> interfacing with different vlans?

Maybe that's the wrong question. What is the problem you are trying to
solve? Maybe link local addresses are not the right tool...

Regards,
 Roland



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