Re: tap interface forcing a permanent ARP association

Paul Procacci <pprocacci@gmail.com> writes:

> The difference is shown in the flags:
>
> tap0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0
> mtu 1500
> vs
> tap0: flags=8803<UP,BROADCAST,SIMPLEX,MULTICAST> 
>
> UP is the administrative state indicator, or what you have configured the NIC
> to do.
> RUNNING is the operational state indicator, or what the NIC has actually been
> able to do.
>
> UP without RUNNING means the NIC is not detecting a link.
>
> So what does this mean to me? I'd interpret this to mean the first tap0 you
> provided is connected to something while the second one isn't.

It is all more simple and more stupid than that: "up" lower case is
interpreted as the paraameter to mark the interface "up"; while "UP" in
upper case is interpreted as the FDQN that should be associated to the
interface (even if it is not really FDQ).

Thank you,

Olivier
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