IRB Routing over EVPN-VXLAN on Juniper QFX10K is now officially supported by Juniper! EVPN master Tom Dwyer informed me that support had been added. A quick check on the VXLAN Constraints page confirms the same. Although, note that IS-IS is still not yet officially supported.
So, what’s the use case? Let’s say there’s a vSRX, hosted in a blade chassis environment, which requires dynamic route updates from the core network. The blade chassis is connected to an EVPN-VXLAN fabric via multi-homed layer 2 uplinks utilising EVPN ESI. In order to establish a BGP peering with the core network, the vSRX must peer with the SPINE devices via the EVPN-VXLAN fabric.
This article explains how to establish an EBGP peering between a QFX10K IRB interface and a vSRX in an EVPN-VXLAN environment. The vSRX is hosted in an ESXi hypervisor, which is connected via LEAF1 and LEAF2. A /29 network is used on VNI300 and an EBGP peering is established between SPINE1 & vSRX1 and between SPINE2 & vSRX1. A default route is advertised by both QFX10K SPINEs towards vSRX1.