[c-nsp] Routing Question

[Joseph Hardeman]

Hey Tony and Gert,

Now this is getting interesting, I wasn't aware that you could run VRF's
without MPLS, I have just recently gotten the Cisco routers and don't know
everything about them or the Cisco configurations I can use.  Once I get
some time today, I will start looking into how to set it up.  If you have an
example of how to set this up, that would be awesome to see.  Or a link that
you could send me, but I believe I would have to do something like the
following:

Setup the VRP instance on the router, use iBGP to pull the BGP routing table
from the router itself, then use either local-prefs or weights to set the
BGP peers I want to use on that instance higher than the others, then after
that is setup, and this is another point I will need to figure out,
associate the different vlans to that VRF, I believe that should be similar
to the k9 unit setup for passing the couple of VLANs we have using it.
Although that does bring up another question, how to tie the k9 unit into
the two VRF's so that I can do the filtering and then route out the
different BGP paths.  I believe I have an idea on how to do it, but wanted
to ask these questions because you guys know a lot more than I do on how
this can be setup and how it will work.  :-)

Thanks for everything

Joe


On Fri, Jun 3, 2011 at 3:32 AM, Gert Doering <gert at greenie.muc.de> wrote:

> Hi,
>
> On Thu, Jun 02, 2011 at 10:28:27PM -0400, Joseph Hardeman wrote:
> > Thanks for the reply, I was hoping there was some way to do it with
> > Local-Prefs or weights setting the BGP routes from peers into a group and
> > then selecting that group from the routing table for the internal IP
> Range I
> > want to use those routes.
>
> There is only one routing table.  And no way to select different bits of
> it according to source address (unless you use policy routing, but that
> won't easily do what you want either).
>
> > I presume there is a way to setup VRFs to do this?
>
> Yes.  As Tony already explained, VRFs are to a router what VLANs are to
> a switch - the router is divided into multiple virtual routers, and all
> of them have their own routing table.
>
> So you put one set of source machines into VRF blue and the other into
> VRF red, and then you can pref the routes individually to whatever you
> want.  Getting the routes into the VRFs depends on your router setup,
> and can be its own challenge.
>
> > Or how would that work?  I believe VRFs are specific for an MPLS
> > network and I have never touched or set one of those up before.
>
> MPLS is just one possible option to transport VRF-belonging packets to
> other routers (like "dot1q tagging for VLAN-packets", in a way).  But
> the VRF functionality is independent of MPLS, and you could, for example,
> connect multiple VRF-enabled routers via a dot1q trunk, with every VLAN
> interconnecting one of the VRFs.  (This gets impractical after a few
> VRF instances, and MPLS/LDP/BGP-AFI-VPNv* makes this all automatic).
>
> gert
> --
> USENET is *not* the non-clickable part of WWW!
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> Gert Doering - Munich, Germany
> gert at greenie.muc.de
> fax: +49-89-35655025
> gert at net.informatik.tu-muenchen.de
>