350-601: Implementing and Operating Cisco Data Center Core TechnologiesDemo

Prefixes exported from a VRF carry that VRF's export route target, and a receiving VRF imports only prefixes whose route target appears in its own import list, so two-way prefix exchange requires each PE's export RT to match the other PE's import RT. That condition is met when both PEs import and export the same value (RT 233:1 on each side, with distinct route distinguishers), and equally when the values are crossed — one PE exporting 233:2, which the peer imports, while importing 233:1, which the peer exports. A configuration in which one side exports a route target that the other side never imports leaves that direction blocked. Route distinguishers serve only to keep overlapping prefixes unique in BGP and do not need to match between PEs.