A municipal leaf advertises EVPN routes for a VNI, but peer leaves have no matching route-target import. What is the likely learning result?
Select an answer to reveal the explanation.
Short Explanation
Route targets are the membership badges on EVPN routes—if the other leaves never import your badge, they politely ignore your MAC/IP ads. The routes can leave the speaker and still go nowhere useful. That is a control-plane policy miss, not a cosmetic SNMP issue.
Full Explanation
When a municipal leaf advertises EVPN routes for a VNI but peer leaves have no matching route-target import, peers do not install those EVPN routes into the corresponding MAC-VRF or IP-VRF, so remote MAC/IP learning for that membership fails despite the advertisement existing. Route targets define EVPN membership policy; export without matching import is the classic “advertised but not learned” failure mode on county fabrics.
Peers do not import every EVPN route globally because VNIs alone bypass route-target policy. Spines do not rewrite route targets automatically so import policy on leaves never matters. Route-target mismatch is not limited to SNMP traps—it directly affects overlay forwarding tables for the tenant.
Exam caveat: RT import/export alignment is mandatory for EVPN learning; VNI identity does not override route-target policy on JN0-683 items.
Operational check: compare export RT on the advertising leaf with import RT on peers; correct the mismatch; confirm Type-2 routes install into the MAC-VRF and remote MAC forwarding resumes for the civic VNI.
In civic fabric operations, retain the correct idea—Peers do not install those EVPN routes into the corresponding MAC-VRF/IP-VRF, so remote MAC/IP learning for that membership fails despite the advertisement existing—and reject distractors that confuse layers or tools. Specifically, do not treat “Peers import every EVPN route globally because VNIs alone bypass route-target policy.” as valid, do not accept “Spines rewrite route targets automatically so import policy on leaves never matters.” as a substitute design, and do not operationalize “Route-target mismatch only affects SNMP traps and never overlay forwarding tables.” in production runbooks. Re-validate after changes with show commands for sessions, routes, VTEP reachability, and a simple tenant traffic test appropriate to the VNI under review.