From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rask Ingemann Lambertsen Subject: Re: network interface cards native vlans support in linux kernel? Date: Wed, 12 Nov 2003 20:48:04 +0100 Sender: netdev-bounce@oss.sgi.com Message-ID: <20031112204804.B968@sygehus.dk> References: <20030709152814.GC15293@gtf.org> <20031022140624.A9145@vip.cybercity.dk> <3F96B7FD.7080607@candelatech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: To: netdev@oss.sgi.com Content-Disposition: inline In-Reply-To: <3F96B7FD.7080607@candelatech.com>; from greearb@candelatech.com on Wed, Oct 22, 2003 at 10:01:49AM -0700 Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Wed, Oct 22, 2003 at 10:01:49AM -0700, Ben Greear wrote: > Rask Ingemann Lambertsen wrote: > > > > What does a driver need to do to make sure it can handle vlan frames? Is it > > enought to be prepared to handle frames of size dev->mtu+4? How do I know 4 > > bytes will be enough tomorrow when someone introduces VLAN2 with a 64-bit tag? > > Checking for CONFIG_VLAN is of no use, right? > > It needs to be able to handle 1518 bytes (+crc), send and receive. I'd > suggest using the Intel e100 or e1000, as they both support VLANs just fine. > Most other GigE nics work too. I was thinking about what to do as a driver *writer* rather than as a driver *user*. #include and allocating buffers of (dev->mtu + VLAN_ETH_HLEN) bytes. Some chips, such as the Tulip series, need an extra 4 bytes for the CRC when receiving. -- Regards, Rask Ingemann Lambertsen