Virtual Extensible LAN (VXLAN) Tunnel Improvements

For ExtremeXOS 22.5, a number of enhancements have been added for VXLAN that support routing in and out of tunnels (RIOT).

Tenants may have multiple overlays across a data center network where different VLANs belonging to the same tenant are mapped to different VXLAN Network Identifiers (VNIs). Tenants require routing between the VLANs, and VXLAN gateway nodes would need to act as Layer 3 gateways that are capable of routing traffic between tenant VLANs. Inter-overlay routing involves routing:

Routing traffic from a tenant VLAN into a tunnel with the destination overlay‘s VNI.
Routing traffic from a tunnel to a tenant VLAN that is different from the tenant VLAN associated with the VNI in the received packet‘s VXLAN header.
Routing traffic from a tunnel to the same or different tunnel.

A VXLAN tunnel endpoint (VTEP) is designated as the gateway for an overlay by manually configuring it or by running a first hop redundancy protocol (FHRP), such as Virtual Router Redundancy Protocol (VRRP) on the tenant VLAN on the gateways and letting the protocol determine the placement of the router.

The following enhancements are included in ExtremeXOS 22.5 to support RIOT:

Enable IP forwarding on tenant VLANs.
ExtremeXOS switches route traffic from an access VLAN to another access VLAN where either or both access VLANs are configured to be VXLAN tenant VLANs.
Initiate ARP requests across VXLAN tunnels.
Learn ARPs from encapsulated ARP responses received on VXLAN tunnels.
Static ARP configuration with neighbor reachable over tunnel.
ExtremeXOS switches route tenant traffic from access VLANs into VXLAN tunnels, and VXLAN tunnels to access VLANs.
VRF support for overlay VLANs.
Underlay and overlay have separate time to live (TTL) spaces (inner TTL is decremented by 1 at the Layer 3 gateway at tunnel initiation).
Underlay and overlay networks have a common Differentiated Services Code Point (DSCP)/Type of Service (ToS) space.
Layer 3 gateway functionality in conjunction with Virtual Router Redundancy Protocol (VRRP). Layer 3 gateway is VRRP master (ExtremeSwitching X690 series switches only).
Static overlay route configuration with tunnel next hops.

Supported Platforms

The VXLAN enhancements (unless otherwise noted) are supported on the Summit X770, X670-G2, and ExtremeSwitching X870, X690 series switches, and stacks with X770, X670-G2, X870, and X690 slots only.