On Mit, 2007-10-10 at 15:55 +0200, Hannes Gredler wrote:
> On Wed, Oct 10, 2007 at 03:31:40PM +0200, John Hay wrote:
> | On Wed, Oct 10, 2007 at 02:48:27PM +0200, Mitar wrote:
> | > Hi!
> | > 
> | > On 10/10/07, Bernd Petrovitsch <bernd@firmix.at> wrote:
> | > > Short: I had (on a stock Linux kernel) no problems with > 1 default
> | > > route.
> | > 
> | > I can second that. I also have good (working) cases of Linux based
> | > nodes with VPN and Internet uplink working nicely together with OLSR.
> | > But on Linux you can declare multiple default gateways (with different
> | > metrics). On Mac OS X this is something nonexistent (if I understood
> | > things correctly).
> | 
> | It is nonexistent on FreeBSD also. I think the thinking is that an app
> | (like a routing daemon) is much better at deciding when to use what,
> | than the kernel can.
> 
> hmm not really .. that thinking implies that there is only one source
> (routin daemon) supplying routing information.

Yes.
And that is clearly not always the case (and it's even worse IMHO;-) -
see below).

> like bernd has described many of us olsrd
> developers use a openvpn tunnel to some olsr cloud to get a link-state
> feed in order to test olsrd. here i already have two sources
> for the default route ... one (static) to my ISP and another one
> pointing over the openvpn (tap) interface.

The root of the problem is IMHO:
First, we have two different "layers" of routing:
- "pure" IP routing in the tech-only domain. One uses e.g. RIP, OSPF for
that.
- administratively limited routing (which - as a consequence - must be
configured
  by a human) usualy at the border of an AS: BGPv4 is state of the art
there.
[ Technically, BGPv4 as such is not necessary and one could - pure
technically
seen - use OSPF there. But usually you have at least to pay there so you
want/need
it controlled. ]

These annoying home users (like /me) are sitting on such an
administrative border -
without need for BGPv4 because I have only one IP-address and my cable
provider
probably doesn't want to route through my node anyways;-) (and I have
lots of
firewalls rules there too). But I have also one of the tech-only domain
routers
on exactly the same host.
Thus there is no single daemon on my node which controls all of the
routing
(because "cable client part is quite statically configured - especially
the
firewall).
I probably could install and use Quagga and have such a single route
controlling instance on my node but up to now it was not necessary (and
it
saved time and brain capacity to not learn the next tool).

	Bernd
-- 
Firmix Software GmbH                   http://www.firmix.at/
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