Re: vlan Q in Q - [WAS Re: Using a switch fabric to emulate multiple NICs]
Ben Greear <[email protected]>
| Newsgroups | gmane.linux.drivers.vlan |
|---|---|
| Organization | Candela Technologies |
| Message-ID | <[email protected]> |
Alex Zeffertt wrote: > O > >>>I'd appreciate any comments regarding how this should be done properly. >> >> From a brief glance at the code, I bet that a program opening a raw socket and passing >>a pre-constructed VLAN packet to the VLAN device will cause double encapsulation, which >>is not what I would want to happen. If we do not add the additional 4 byte header when >>the VIDs are the same, I believe that would fix that problem. It would create a small >>problem for your device in that the users could not use the VLANs that your >>box uses internally. >> > > > > Thanks for having a look Ben. > > I think I am missing something though. Why would a program ever want to pass a "pre-constructed > VLAN packet" to the VLAN device. I assumed that the whole idea was to make vlan devices look like > traditional ethernet devices to the rest of the kernel. Well, on a regular ethernet device, you can open a raw packet socket and pass a pre-constructed frame. My original thought was to allow the same thing on VLANs. However, I can understand arguments for your approach. I guess we could just let application writers know to pass a pre-constructed *ethernet* frame instead of a VLAN frame. It is likely that this is how folks use it anyway... Ben > > Alex > -- Ben Greear <[email protected]> Candela Technologies Inc http://www.candelatech.com