SR OS supports the three IP-VRF-to-IP-VRF models defined in draft-ietf-bess-evpn-prefix-advertisement for EVPN-VXLAN and EVPN-MPLS R-VPLS services. Those three models are known as:
interface-less IP-VRF-to-IP-VRF
interface-ful IP-VRF-to-IP-VRF with SBD IRB (Supplementary Bridge Domain Integrated Routing Bridging)
interface-ful IP-VRF-to-IP-VRF with unnumbered SBD IRB
SR OS supports all three models for IPv4 and IPv6 prefixes. The three models have pros and cons, and different vendors have chosen different models depending on the use cases that they intend to address. When a third-party vendor is connected to an SR OS router, it is important to know which of the three models the third-party vendor implements. The following sections describe the models and the required configuration in each of them.