[c-nsp] Design issue for customer with dual MPLS links

[Phil Mayers]

jack daniels wrote:
> Hi Guys,
> 
> This is a paticular design issue I'm facing with customer where I have a lot
> of constrainits .
> 
> Topology
> 

The diagram is a bit mangled, at least for me...

> 
> MPLS CLOUD (ISP1)
> MPLS CLOUD (ISP2)
> |
> |
> |
> |
> |
> |
> CE1
> CE2
> |
>                     |
> |--------------------------------PIX525
> (CLUSTER)---------------------------------
>                                     |
>                                     |
>                                     |
>                                   LAN ( 6509 catalyst switch - runnning
> HSRP)
> 
> 
> Issue - I want  to go out via ISP1 and come back via ISP1 ......Backup is
> CE2
> 
> When traffic reaches PIX cluster how will it decide whether ISP1 is UP and
> traffic is not blackholed......How will PIX cluster decide to FWD traffic to
> ISP2.
> 
> Now for this solution , constraints are -
> 
> 1) I cant run HSRP on CE1 and CE2
> 2) Cant run run dynamic routing on PIX
> 3) IP SLA also can't also be used on PIX cluster

Oh good. An easy question </sarcasm>

Seriously - go back to the customer and re-negotiate the constraints.

Failing that - use something like EEM on CE1 to drop the physical link 
from CE1->PIX if the internet goes away, and on the PIX, have two static 
default routes - a low-cost one pointing to CE1 and a high-cost pointing 
to CE2.

This assumes the link from CE1->PIX is an actual physical link. It 
obviously won't work if it goes via a layer2 switch.

But HSRP or routing are the "best" ways to solve this.