VXLAN EVPN Distributed Anycast Gateway

Because of EVPN and VXLAN, we have the Distributed Anycast Gateway feature, enabling the VTEPs in the VXLAN EVPN network to perform both bridging and routing.

Benefits of Distributed Anycast Gateway:

• Optimal east-west traffic forwarding.
• Support transparent virtual machine mobility across the VXLAN fabric.

Now we know the benefits of Anycast Gateway.

What is the Distributed Anycast Gateway?

Distributed Anycast Gateway is feature for EVPN VXLAN, which enables all the VTEPs that are part of VXLAN network to use the same gateway IP addresses.

So hosts in a VNI can find their gateway locally on the VTEP which they are connected.

Without Distributed Anycast Gateway:

Imagine if we don’t have Distributed Anycast Gateway deployed in the network, and some VTEPs are configured as a gateway for some VNI, and others are configured as gateway for other VTEPs. The traffic flow would be inefficient, causing unnecessary hops and delays.

Without Anycast Gateway In the above scenario, VTEP-1 configured as gateway for VNI-RED, and VTEP-2 configured as gateway for VNI-Green.

So when Host-A need to communicate with Host-B, in this VTEP-1 will receive traffic fromHost-A then it forwards it to Host-B gateway at VTEP-2, VTEP-2 will forward it back again to VTEP-1, then VTEP-1 will decapsulate the tunnel and forward it Host-B.

With Distributed Anycast Gateway:

If Anycast Gateway is distributed across all VTEPs, the traffic flow is optimized. Host-B is only one-hop away from Host-A, as all gateways are configured on all VTEPs. This ensures efficient VXLAN routing and bridging.

Host-B is only one-hop away from Host-A, as all gateways now are configured on all VTEPs.

Conclusion:

Distributed Anycast IP Gateway for VXLAN overlay networks enables optimal VXLAN traffic routing across the Layer 3 network.

It also supports seamless VM mobility because the same virtual MAC and IP addresses are configured on all VTEPs, eliminating the need for the host to initiate ARP requests for its gateway.

#EVPN #VXLAN #DistributedAnycastGateway #VTEP #NetworkingSolutions #NetworkOptimization #VMmobility #Layer3Routing #NetworkEfficiency