proxy-macip-advertisement

Syntax

Hierarchy Level

Description

Enable the proxy advertisement feature on a QFX Series switch that can function as a Layer 3 gateway. With this feature enabled, the Layer 3 gateway advertises the MAC and IP routes (MAC+IP type 2 routes) on behalf of Layer 2 VXLAN gateways.

In an Ethernet VPN-Virtual Extensible LAN (EVPN-VXLAN) centrally-routed bridging overlay (EVPN-VXLAN topology with a two-layer IP fabric), spine devices typically function as Layer 3 VXLAN gateways, and leaf devices typically function as Layer 2 gateways. In this overlay network, the Layer 2 VXLAN gateways can advertise only the MAC routes (EVPN type 2 routes) for the attached hosts. Since the Layer 2 gateways are unable to resolve the MAC-to-IP bindings for the hosts, each of the Layer 3 gateways rely on the Address Resolution Protocol (ARP) and the Neighbor Discovery Protocol (NDP) to discover and install the bindings.

For example, after a Layer 3 gateway receives a host MAC route advertisement from a Layer 2 gateway, and ARP and NDP resolve the MAC-to-IP bindings, the Layer 3 gateway in turn advertises the host MAC and IP routes along with the next hop, which is set to the Layer 2 gateway to which the host is attached. Upon receipt of this advertisement, Layer 2 and 3 gateways in the topology install the MAC-to-IP bindings along with the associated next hops. When any of these gateways receives a packet with a destination MAC that matches an address in its MAC table, the gateway can check the next hop associated with the MAC address and forward the packet directly to the Layer 2 gateway to which the host is attached. This resulting packet flow eliminates the need for the packet to be forwarded first to a Layer 3 gateway, which then forwards the packet to the Layer 2 gateway.

Enable this feature in a centrally-routed bridging (CRB) overlay fabric. With the proxy-macip-advertisement setting, the Layer 3 gateway device manages learning and aging for the ARP and IPv6 neighbor discovery entries.

We recommend that you don't use this feature in an EVPN-VXLAN edge-routed bridging overlay (ERB) fabric with anycast IRB addresses. Using this option in ERB fabrics results in IP reachability issues because remote ARP entries are deleted when they age out, and when using anycast IRB addresses, ARP replies don’t reach the device that initiated the ARP request.

Required Privilege Level

interface—To view this statement in the configuration.

interface-control—To add this statement to the configuration.

Release Information

Statement introduced in Junos OS Release 15.1X53-D60.