We have seen how iBGP was used to do the IP Clos with a RR Setup, how about eBGP.

Configurations / EVE Topology – https://github.com/r2079/JDC

Two simple rules

  • All spines have connections to all leaves – eBGP
  • No leaf or No spine devices have interconnected BGP.

Here is the topology.



The picture says 1000 words here – How the physical links are connected that’s how the bgp flows.


Lets see the BGP Status on R1 and R2


Since the hurdles of multipath has been explained. The use ADD-Path is not required here, instead since the update comes from Different AS numbers (R4 and R5) giving out the same update, we have to use another knob called MULTIPLEAS. This has to be on all Spine and leaf devices so that proper Load Balancing can be done along with EXPORTLB policy in the forwarding table.

Lets see one of the routers


Verification from R6