In Juniper’scampus fabric architectures, the location of theLayer 3 gateway(IRB) differentiates between CRB and ERB models:

Centrally-Routed Bridging (CRB):L3 gateways are placed at thecore layer.

Edge-Routed Bridging (ERB):L3 gateways are placed at thedistribution layer, closer to the edge.

“In the ERB model, Layer 2 gateways are deployed at the access layer, andLayer 3 gateways are deployed at the distribution layer.”

Option A (CRB):Incorrect — L3 is at the core, not distribution.

Option B (IP Clos):Incorrect — in 3-stage Clos, L3 is pushed to the access layer.

Option D (EVPN multihoming):Incorrect — this is about redundancy, not gateway placement.

Option C (ERB):Correct — L3 gateways sit at thedistribution layerin the ERB architecture.