On Tue, Feb 26, 2002 at 06:14:18PM -0000, Kevin Gannon wrote:
> <snip>
>
> >
> > My question is will the Cust PE tag the customer traffic with a label to
> get
> > the
> > trafic to the Agg PE by following the default router and then will the
> label
> > be popped
> > off and another L3 lookup be done and a new tag attached to get the
> traffic
> > to the
> > destination Agg PE.
>
> So something like
>
> CE---PE1----PE2---P---( cloud )
> ^ ^
> cust PE |
> agg PE
> We are looking at label exchange rather than matching VRFs on both the
> PE's. Mind you that might be an idea ...... :o).
>
> Maybe you could tell me a little more about the label exchange scenario
> between the two PE's. We do not want to run OSPF to the second PE (PE1)
> as we are conecerned about OSPF stability. Just as a ball park figure
> we might be talking 700 PE1's.
700 PE1s on a single PE2, or across the whole network?
You have a whole bunch of choices, not all of them palatable or
reasonable. In no particular order:
- LDP + IGP
- LDP + static routes
- EBGP + labels (rfc3107)
** due out Real Soon Now, as I understand it
- Carrier's Carrier (LDP + {IGP|static routes} in a VRF)
- back-to-back VRFs
- Inter-provider BGP (EBGP AF_VPNv4)
Not wanting to run an IGP leaves you with statics+LDP, b2b VRFs (aka
'vrf lite') or the various BGP solutions. If you have 700 PE1s on a
single PE2, you've kinda painted yourself into a corner - you'll need
statics or b2b VRFs, I think.
> Maybe you could explain "no provisions that a default route is
> treated differently than any other route" in the above context. Any
> comments most welcome as my head hurts at this stage.
If PE2 sends a label via some mechanism to PE1 and the label mapping
is for 0.0.0.0/0, that label will be bound to the route just like it
would if PE2 send a label mapping for the address 10.0.0.0/8. You may
need to configure 'mpls ip default-route' on PE1; I'm not sure why
that knob is there but it's off by default.
eric
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