[j-nsp] MPLS Endpoint Discussion

[Ben Dale]

> On 3 Jul 2015, at 12:25 am, Levi Pederson <levipederson at mankatonetworks.net> wrote:
> 
> All,
> 
> I've created simpler MPLS ring between a total of 6 MPLS 4550s.  My
> questions what IP do I use for the Label Switched Path Endpoints. I can't
> seem to find a "best practice."
> 
> Specifically this code
> 
> Obfuscated as I'm a little to literal with my descriptions
> 
> set protocols mpls label-switched-path PE2-to-PE1 to 10.254.1.1
> set protocols mpls label-switched-path PE2-to-PE3 to 10.254.1.6
> set protocols mpls label-switched-path PE2-to-PE4 to 10.254.0.4
> 
> 
> Do I use the /30 that exists between the Legs?
> 
> Or should I use the LoopBack0 ?
> 
> My thought would be Leg itself as it creates the path.  But some documents
> state LoopBack.

Always use loopbacks - if the link goes down (or the preceding node), the destination of the LSP goes with it - Junos will not maintain prefixes for downed interfaces.  

You mention this being a ring - if you target the LSP to a loopback, your IGP will provide an alternative path after a failure.

Cheers,

Ben