[lwip-users] Re: [lwip] /dev/tap0

[Adam Dunkels]

On Thursday 18 October 2001 22:23, you wrote:
> I use RedHat 7.1 too. The /dev/tap0 file is not created in the default
> installation, then you must do as root
>
> address@hidden:/dev/ # ./MAKEDEV tap
>
> The tap should be enabled as a module. When the device is opened, the
> kernel creates an interface.
>
> About the kernel version... If I'm not mistaken, there were two devices,
> before: /dev/tun and /dev/tap. Now there is only tap, but you can configure
> it as tun or tap with an ioctl call. If you are interested in programming,
> take a look at the site
>
> http://vtun.sourceforge.net/tun/
>
> which is the official development site for the driver. It should be enabled
> as a kernel module by default, so there is no need for recompilation,
> unless you want to enable driver debug options or such.

Thanks for your info! I should probably add this to the README file in lwIP. 

> I tried to run lwip 0.0.3 under Linux RedHat 7 (2.4 kernel too, I think),
> and it was unsuccessful. I even tried to adapt it to the new tap driver
> using the code sample provided in the tun/tap site, but even when I got it
> working (i.e. opening the device, configuring the IP address of the tap
> interface) lwip didnt work. I dont know if the new version works ok with
> Linux. I will be trying soon. I thought that the Linux side was in
> development (there was a lot of lines commented out).

There have been differences in how the tun and tap drivers work under Linux 
and FreeBSD. When I used Linux (back in the 2.2 days), the tap driver didn't 
need ARP since ethernet MAC addresses wasn't used anyway. In FreeBSD, the tap 
driver works very much like a "real" ethernet, so ARP is needed. If Linux 2.4 
uses the same tap driver as FreeBSD, the current lwIP CVS tap driver code 
could be used for Linux as well as FreeBSD.

> And how did I run lwip? Well, I installed a FreeBSD :-)))

;-)

/adam
-- 
Adam Dunkels <address@hidden>
http://www.sics.se/~adam
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