> > > My 10GbE NIC does not do HW VLAN tag insertion/removal (we concluded > > > there was no performance benefit). On several OSes, I'm forced to > > > claim the device does HW VLAN tag support (and do tag > > > insertion/removal in the driver) to gain support for the 4 bytes of > > > "margin" (1518, 9018), and/or to get the OS to trust that my device > > > can offload checksum in combination with VLAN frames. > > > > > Hmm, can we make the assumption that supporting margin of greater than 4 > > always implies that a driver can handle offload checksum for VLAN frames? > I > > am not sure whether this is always true. > > Maybe there could be a capability flag for checksum offload in > combination with vlan? There seem to be plenty of bits free in the > 32-bit cap data for MAC_CAPAB_HCKSUM. >
This sounds possible, or at least a similar mechanism is needed to make sure hardware checksum works fine for VLAN frames. Thanks! - Cathy _______________________________________________ networking-discuss mailing list [email protected]
