[c-nsp] Internet in VRF

[Mark Tinka]

On 30/Apr/15 18:41, Mike wrote:
> Hi,
>
>     I'd like to ask for the collective opinion on routing in service
> provider network serving broadband subscribers:
>
>     I have an ASR1k and will be terminating PPPoE broadband
> subscribers here. I'll also be terminating my primay internet feed
> (BGP) here, and I the future I will have 3 providers and will be
> multihomed. I also will have some MPLS vpns for certain customers.
>
>     I think I want to have my default routing table carry mostly
> loopbacks and direct interface connected routes, while I want to stuff
> everything else into VRF's. Those other VRF's are likely to be
> Internet (full tables), Subscribers (all the /32's for PPPoE
> subscribers), and the odd vrf for any mpls vpn customers.  The
> challenge is that - I think - I would want to only leak a default
> route into any other non-Internet VRF that requires shared service
> access to it, which should keep the table sizes down. My question is,
> does this sound reasonable? Is there any reason I wouldn't want to set
> things up this way?

I like simple.

Internet routes in a VRF is not simple - too dependent on hardware and
software capabilities, without having to worry about what the vendors do
with the hardware or the software in future revisions.

I know a few ISP's that went this router back in 2003, when MPLS was
all-the-rage; they're finding that tearing down this wall of complexity
is the way forward, but alas, mighty painful.

Mark.