[c-nsp] Hierarchical FIB on Cisco 7600

[Cydon Satyr]

I see. But then is there any effect of having repair path installed with
"bgp additional-paths install" command on platform without Hierarchical
FIBs or is it purely cosmetic?

Thank you again :)


On Sat, Apr 26, 2014 at 8:00 AM, Oliver Boehmer (oboehmer) <
oboehmer at cisco.com> wrote:

>
> >Thank you all; so let me just see if I got this right.
> >
> >If we're not loadbalancing with IGP (instead there's primary/backup
> >uplink)
> >on edge, and not using H.FIB (with cef table output-chain build favor
> >convergence-speed) and we're running full BGP table on edge routers,
> >anyone
> >with experience on how would flat FIB affect convergence without PIC Core
> >on 7600? In other words what would be real life effect of rewriting couple
> >of hundred thousand entries to point to new output interface in terms of
> >convergence?
>
> I don't have a recent performance study, but I saw a 7600 w/ 200k IPv4
> prefixes taking ~17 seconds to rewrite all prefixes, where hierarchical
> FIB cut this down to < 1 sec.
>
> >
> >If you don't mind, could you explain part with "VPNv4 requires recirc" ?
> >I'm not sure what does that mean in relation with PIC Core?
>
> it means it'll cut the pps performance in half for vpn traffic with H.FIB.
>
> >
> >And if I understand, since we're already installing in CEF 'repair' path
> >in
> >PIC Edge scenario, then H.FIB is not really required?
>
> It is. We can't leverage the repair path unless we have a hierarchical FIB
> structure.
>
>         oli
>
>
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