[j-nsp] Prefix independent convergence and FIB backup path

[Mark Smith]

On Thu, Feb 8, 2018 at 3:42 PM, Olivier Benghozi
<olivier.benghozi at wifirst.fr> wrote:
> Here (VPNv4/v6, BGP PIC Core + PIC Edge, no addpath as not supported in vpn AFI) we can see that, when possible:
> active eBGP path is backuped via iBGP path
> active iBGP path is backuped via another iBGP path
>
> We don't see:
> active iBGP backuped via inactive eBGP
> active eBGP backuped via another inactive eBGP

Ok, so this is the same that I see. Maybe IBGP->EBGP PIC will be
supported in some future junos version :)


> Note that in your case (in inet.0) there's no BGP PIC Edge feature, as I understand it's just a special PIC feature needed for labelled paths toward outside, and you can see that BGP PIC Core for inet already covers your eBGP routes in inet.0.

This edge/core terminology is not very clear. As stated in the
documentation [1] and "MPLS in the SDN era" book (page 801-802)
"protect core" is actually PIC edge.


> Also note that in your case, PE2 (at least when using NHS) cannot quickly detect a TRA1 loss anyway, so there's no usecase here, in fact...

This is correct, thanks for clarification.


> Of course you already know that having both TRA1 and TRA2 with the same localpref does the trick (even without addpath), but it's not what you intended to test :)

Yes I do and I tested it too. Failover was approx 1-2 seconds.
Maybe this is the way to go in production. There may be reasons why
one does not want to "load-balance" between transits though.


[1] https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/protect-core-edit-routing-instances.html