Are ./valte-ctl and ./bridge friends or competitors?

[Vincenzo Maffione]

2017-03-20 19:41 GMT+01:00 Harry Schmalzbauer <freebsd at omnilan.de>:

> Bezüglich Vincenzo Maffione's Nachricht vom 20.03.2017 12:50 (localtime):
> …
> >> So to summarize for newbies exploring netmap(4) world in combination
> >> with physical uplinks and virtual interfaces, it's important to do the
> >> following uplink NIC configuration (ifconfig(8)):
> >> -rxcsum -txcsum -rxcsum6 -txcsum6 -tso -lro promisc
> >>
> >
> > Exactly. This is mentioned at the very end of netmap(4):
> >
> > "netmap does not use features such as checksum offloading, TCP
> segmentation
> > offloading, encryption, VLAN encapsulation/decapsulation, etc.  When
> using
> > netmap to exchange packets with the host stack, make sure to disable
> these
> > features."
> >
> > But it is probably a good idea to add these example ifconfig instructions
> > somewhere (man page or at least the README in the netmap repo).
> >
> >
> >>
> >> I guess vlanhwtag, vlanhwfilter and vlanhwtso don't interfere, do they?
> >>
> >
> > Well, I think they interfere: if you receive a tagged packet and the NIC
> > strips the tag and puts it in the packet descriptor, then with netmap you
> > will see the untagged packet, and you wouldn't have a way to see the tag.
>
> Hmm, if I connect a vlan child to VALE (once I provided crash info and
> someone capable fixed it), it's intentional that the tag was removed.
> Otoh, if I attach the parent interface to VALE, stripping isn't done
> yet, even if there are children defined for a specific vlan id.  I see
> all frames tagged on the parent, at least it was so when I checked that
> last time, maybe 2 years ago.  I'm always creating childs with vlan id 1
> if I want a interface without taged frames.


It depends on the NIC hw capabilities.
If you "see" the frames with tcpdump, tcpdump can show you something
different from the packet format.
Anyway, netmap patches just ignore VLAN tags, so that if the NIC does not
strip tags, you will see them in your netmap application.

Cheers,
  Vincenzo


>


> Hope I'm not missing something obvious again, I'm about to call it a day
> here.
>
> Thanks,
>
> -harry
>



-- 
Vincenzo Maffione