Re: VLANs, untagged frames and (i)pf

[Darren Reed <darrenr%netbsd.org@localhost>]

Edgar Fuß wrote:
> I assume these are quite trivial questions, but I couldn't find them answered 
> in any docs. If I missed something, a pointer to a suitable doc would be 
> appreciated.
>
> If I have a vlan attached to a physical interface, am I right to assume that 
> untagged frames will be received on the physical interface and tagged ones with 
> an unassigned tag (i.e. one different from all those for which pseudo 
> interfaces have been assigned) will be dropped?
>
> Now, what about (i)pf on the pseudo and the physical interface? Will tagged frames be 
> "seen" by the filter as travelling through the physical interface or will they 
> only be dealt with on the pseudo one?
>   

Well I wasn't sure about this so I went and tried it.

The packet appears once to IP and on vlan0, so as far as ipf is
concerned, the packet is on vlan0 (the pseudo interface) and not
fxp0 or whatever physical interface it is that the vlan exists on
top of.

Darren