Nokia 4A0-D03 Exam - Topic 2 Question 10 Discussion

Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:

An IRB interface provides the logical L3 gateway function between a Layer 2 MAC-VRF and a Layer 3 IP-VRF on the same PE. It allows locally bridged hosts to route into the tenant IP-VRF while preserving EVPN control-plane signaling for MAC/IP reachability. The IRB subinterface must have at least one IP address because it acts as the routed gateway for the subnet, and it may also be configured with ACLs to apply traffic policy at the L3 boundary. Option B is false because it incorrectly generalizes the IRB relationship. In SR Linux EVPN service modeling, an IRB subinterface connects a MAC-VRF to an IP-VRF in a controlled one-to-one service attachment context; the design is not that both IP-VRFs and MAC-VRFs arbitrarily contain multiple IRB interfaces for the same relationship. A MAC-VRF has its IRB gateway association into the IP-VRF, and the IP-VRF may connect to multiple MAC-VRFs through distinct IRB contexts, but the statement as written is not the correct rule for IRB interface behavior. Reference: SR Linux IRB interface operation, MAC-VRF/IP-VRF interconnection, gateway IP and ACL support.