On Tue, 29 Mar 2005 13:34:57 -0800, Ben Greear <greearb@xxxxxxxxxxxxxxx> wrote: > Peter Stuge wrote: > > On Tue, Mar 29, 2005 at 08:59:08AM -0500, Joe Cooley wrote: > > > >>Hello, > >> > >>I'd like to disable 802.1q tag stripping on my linux 2.6 box so that > >>I can see the tagged packets on the physical device, e.g. eth0, > >>while seeing the stripped version on the vlan device, e.g. eth0.10. > >>I first tested to see if this behavior was present. Unfortunately, > >>it was not. > > > > > > Not even when you put eth0 into promiscuous mode? It did not work in promiscuous mode. This is because I had a vlan configured (ethX.Y) on the physical port through which I was attempting to receive tagged-intact packets. Through further investigation, I figured out that the Intel NICs provide a filtering and stripping capability, which is enabled if *any* vlans are configured on the physical port. This means that all but the packets associated with configured vlans will be passed to the OS from the nic, and in tagged stripped format. The NIC performs the stripping. > > If not, you'll probably have to do something to the driver. > > > > Also, to get the most reliable results, I suggest that you have a > > separate system monitor the trunk. > > I think it's a simple edit to the driver file to change a #define > and then re-compile. It's possible that ethtool has a way to change > it real-time as well... I poked around some more in the driver file, and played around with ethtool. I found with ethtool that the eeprom could be changed, but it wasn't clear to me that that was necessary. The settings don't appear to be in eeprom, but rather, I think they reside in a set of registers that I don't seem to have write access to with ethtool. Now that I've figured out the filtering and stripping behavior of the nic, I may try to set something up so that I can use ethtool to enable/disable filtering and stripping and decouple their configuration from one another. Joe > Ben > > > > > > > //Peter > > _______________________________________________ > > Vlan mailing list > > Vlan@xxxxxxxxxxxx > > http://www.lanforge.com/mailman/listinfo/vlan > > > > -- > Ben Greear <greearb@xxxxxxxxxxxxxxx> > Candela Technologies Inc http://www.candelatech.com > > _______________________________________________ > Vlan mailing list > Vlan@xxxxxxxxxxxx > http://www.lanforge.com/mailman/listinfo/vlan >
