Introduction
Figure 2-1 shows
the Control Plane operation when host EP1 using IP 172.16.100.10/32 joins the
network. In the previous chapter, we saw how Edge-xTR-11 learned the IP address
and registered it to MapSrv-22 by using the LISP Map-register Message where the
Instance-Id 100 represents Virtual Network-Id (VN-Id). MapSrv-22, in turn,
advertised the NLRI to Border-PxTR-13 as BGP VPNv4 Update message where
extended community RT 1:100 (=VN-Id) is used as a kind of VPN identifier (BGP
VPNv4 route import/export policy is based on RT value). This chapter first
explains how Border-PxTR-13 sends BGP IPv4 Update message to local SD-WAN
device vEdge-1. The eBGP peering between Border-PxTR-13 and vEdge1 is VRF based
and BGP updates over it don’t carry any VN-Id. vEdge-1 imports the routing
information from BRIB to RIB. Then it advertises the routing information by
using OMP (Overlay Management Protocol) to the SD-WAN centralized Control Plane
vSmart over the DTLS tunnel using System-IP as an originator-Id and VPN label
1003 as a VN-Id. vSmart forwards this update to SD-WAN device vEdge-2 located
in Datacenter. vEdge-2 installs the route into the routing table. After that,
it exports the routing information from the RIB to the BGP process and sends
the BGP IPv4 Update message to Border-Leaf-13 over VRF NWKT eBGP peering
without VN-Id.
Figure 2-1: Overall Control-Plane Operation.


