[Xorp-hackers] VLANs

[Kristian Larsson]

On Tue, May 09, 2006 at 12:58:20AM -0700, Pavlin Radoslavov wrote:
> > Vyatta have had working VLAN support for some time
> > now. Is there anyone having any objections
> > backporting this into XORP?
> > I know the support is only for Linux, but by
> > starting with the Vyatta code we can work our way
> > from there.
> 
> In general, we would like to port-back (as time allows us) many of
> the good things the Vyatta folks have added to their code.
> 
> However, in case of VLAN specifically, the Vyatta solution won't
> work for us, because it is not portable. E.g., the interfaces.tp
> rtrmgr template file contains the following %create commands which
> deal with creating VLAN vifs:
> 
>         %create:  program "modprobe 8021q";
This makes sure the 802.1q module is loaded in the
kernel. I don't really think it is the job of XORP
to make sure the underlying operating system has
support for .1q, it is the responsibility of the
administrator. I for one would not use a module
but rather compile the support into the kernel.
>         %create:  program "vconfig add $(ethernet.@) $(@)";
This is certainly not an elegant solution.
However there is no problem doing this from within
the fea. I've provided a very simple code example
of adding vlans on a Linux system, it's available
at
http://www.xorp.org/bugzilla/attachment.cgi?id=79&action=view

> Those external commands are Linux specific and we cannot use them in
> XORP. Implementing it portably eventually means that we need to add
> the appropriate support to the FEA, and this is not a trivial task.
Yes I am aware of this. But I feel that we should
try to move in the "right" direction, whichever
direction that is.

And to be honest I don't really see the "non
trivial" parts of this as long as you're confident
with C it shouldn't be a problem, right ;)

   Kristian.