Re: draft-eng-nalawade-ospf-tunnel-cap-00.txt

[Rahul Aggarwal <[e-mail]>]

Hi Gargi,

> its domain using an IGP and redistribute only the inter-AS information on
> the border PEs.

This is another flaw with doing this in IGP. A BGP only solution doesn't
require redistribution between IGP and BGP.

>
> Not necessarily. Depends on the application. You are narrowing down the scope
> to a particular application - which is why you think PE. I agree that common
> scenarios would be PE-to-PE. But that does not mean that there won't be scenarios
> that have P routers as endpoints. TE-tunnels is one example.
>

Please explain how/why tunnel capabilities will be used by TE tunnels.


> Also note that this draft is a framework for tunnel endpoint signalling and
> how and where it is deployed/used and whether the tunnel endpoints are PEs
> or Ps depends on the specific application a Provider or an Enterprise has
> in mind.
>

Can you articulate the applications where this information is needed on
the P routers ?

> > > learnt through an IGP to resolve the nexthop to BGP prefixes. But in
> > > the presence of tunnels, this reachability is not sufficient
> > and the
> > > reachability via the tunnels has to be propagated as well.
> >
> > For route resolution, the BGP next-hop needs to be reachable. The BGP
> > next-hop will be the tunnel endpoint address. This in turn will be an IGP
> > route. Why is this not sufficient ?
>
> Because the reachability would be through the tunnel. Unless the tunnel

The control traffic reachability is through the hop by hop path to the
tunnel endpoint. Data traffic takes the tunnel.

Thanks,
rahul