In this section, we focus on the second IRB operation model: the asymmetric model. Asymmetric IRB, like symmetric IRB, is used to interconnect Layer 2 and Layer 3 in complex network environments. The key distinction lies in the processing method: in asymmetric IRB, the ingress Provider Edge (PE) performs a sequence of three lookups—MAC, then IP, then MAC again—while the egress PE only conducts a single MAC lookup. That's also why BGP EVPN RT-5 is not tested in this test case: the egress DUT checks only MAC-VRF.
We validated both testbeds by sending end-to-end unicast traffic: first on the EVPN-SR-MPLS testbed, then on the EVPN-VXLAN testbed. In both cases, there was no packet loss.