[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



More information about the Bloat mailing list