Centralized VXLAN IP gateway deployment
NOTE: Centralized VXLAN IP gateways support only IPv4 sites. | ||
As shown in Figure 12, a VTEP acts as a gateway for VMs in the VXLANs. The VTEP both terminates the VXLANs and performs Layer 3 forwarding for the VMs.
Figure 12: Centralized VXLAN IP gateway placement design
As shown in Figure 13, the network uses the following process to forward Layer 3 traffic from VM 10.1.1.11 to the Layer 3 network:
The VM sends an ARP request to obtain the MAC address of the gateway (VTEP 3) at 10.1.1.1.
VTEP 1 floods the ARP request to all remote VTEPs.
VTEP 3 de-encapsulates the ARP request, creates an ARP entry for the VM, and sends an ARP reply to the VM.
VTEP 1 forwards the ARP reply to the VM.
The VM learns the MAC address of the gateway, and sends the Layer 3 traffic to the gateway.
VTEP 3 removes the VXLAN encapsulation and inner Ethernet header for the traffic, and forwards the traffic to the destination node.
Inter-VXLAN forwarding is the same as this process except for the last step. At the last step of inter-VLAN forwarding, the gateway replaces the source-VXLAN encapsulation with the destination-VXLAN encapsulation, and then forwards the traffic.
Figure 13: Example of centralized VXLAN IP gateway deployment