Cisco ACI
VXLAN-EVPN explained: https://www.youtube.com/watch?v=O8wU1qNlsyI http://www.cisco.com/c/dam/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/sdnfordummies.pdf

• VTEP: runs in the leaf swicthes. Distributed gateways (but same IP in all), all arp are in the leafs.

2. It's automatically (I'd say randomly) chosen by the APIC

3. The VTEP IP is automatically (again I'd say randomly) chosen from the pool of infrastructure addresses you have to define when setting up the fabric
VXLANs can use MCAST but most of the solutions are heading to point to point. ARP flooding between different hypervisors

Application Policy Infrastructure Controller (APIC): Implemented as a cluster of three boxes for fault‐tolerance and scalability benefits
ANP (Application Network Profile) is a policy that defines the requirements of the application in terms of network resources and how application components are connected.
Basically designed for cisco 9k but it can interact with other Nexus through 1000V 9k can work on NX-OS move (simple, enhanced, switch) or in ACI move, in combination with an APIC controller
Cisco APIC REST API User Guide: http://www.cisco.com/c/en/us/td/docs/switches/datacenter/aci/apic/sw/1-x/api/rest/b_APIC_RESTful_API_User_Guide.html

• EPG (End Distribution Point). They are like port-groups or port-profiles (~ACLs), provide segmentation among workloads. EPGs contain one or more virtual and physical servers that require similar policy and connectivity. The Cisco ACI fabric allows you to define the communication path among EPGs, just as you do by stitching virtual lines between VLANs using IP routing and access control lists (ACLs). EPG as virtual extensible LAN (VXLAN)/Network Virtualization using Generic Routing Encapsulation (NVGRE) virtual network identifier (VNID)
• Tenant: Within a tenant, you define one or more Layer 3 networks (VRF instances), one or more bridge domains per network, and EPGs to divide the bridge domains.
• Contracts: The communication path between EPGs is managed using the concept of contracts. Contracts define the protocols and Layer 4 ports that can be used for the communication path between two EPGs.

eVPN LEAF AND SPINE fabrics

• ToR router Has routing tables!!
• Even the end ‘host’ runs routing (bgp?). This is because the host is normally a esx host.