> James Bensley
> Sent: Thursday, April 27, 2017 9:13 AM
> 
> It might be worth pointing out that on Cisco you need to enable PIC Core for
> PIC Edge to work at its best. PIC Core as already mentioned is just enabling
> the hierarchical FIB. So for your IGP / global routing table prefixes they 
> will be
> covered by backup paths if they exist (backup path computed and installed
> into hardware FIB).
> 
Don't know about that, on Cisco Edge and Core functionality seems to be joined 
together. 

For instance in IOS or XE FIB hierarchy is enabled by default and can be 
disabled using: 
"cef table output-chain build favor memory-utilization" and re-enabled using 
"cef table output-chain build favor convergence-speed". 
In detail Convergence speed and indirection characteristics are enabled by 
default for the building of Cisco Express Forwarding table output chains (Since 
or beloved 12.2(33)SRA). 

The BGP PIC (Core) is configured using  "bgp additional-paths install". 
The BGP PIC (Edge+Core) feature is automatically enabled by the BGP Best 
External feature. 
When you configure the BGP Best External feature using the bgp 
advertise-best-external command, you need not enable the BGP PIC feature with 
the bgp additional-paths install command.  
The BGP PIC feature does not work with the BGP Best External feature. If you 
try to configure the BGP PIC feature after configuring the BGP Best External 
feature, you receive an error. 
So it's either Core or Core+Edge. 

In XR  cmd "advertise best-external" only advertises best external path and 
does not enable PIC on its own. 
You need to use "additional-paths selection" policy to calculate backup or 
enable PIC (Edge+Core) functionality. 
However the FIB hierarchy is enabled by default. 
Once again no distinction between Core and Edge. 


> For you VPNv4/VPNv6 stuff one must enable PIC Edge with advertise best
> external or add path etc. However enabling PIC Edge without PIC Core means
> that backup paths will be pre-computed but not programmed into hardware. 
Again, not sure how can you enable PIC Edge but not PIC Core on Cisco? 


> In Juniper land, does one need to activate indirect-next-hop before you can
> provide PIC Edge for eBGP vpn4/vpn6 routes?
> 
Nope, just load-balancing. 
And then protection under neighbour stanza. 

> Is indirect-next-hop enabled by default on newer MX devices / Junos
> versions?
> 
Yes. 


adam

netconsultings.com
::carrier-class solutions for the telecommunications industry::


_______________________________________________
juniper-nsp mailing list juniper-nsp@puck.nether.net
https://puck.nether.net/mailman/listinfo/juniper-nsp

Reply via email to