Address Resolution Protocol (ARP) Suppression

Address Resolution Protocol (ARP) traffic makes up a large percentage of broadcast traffic within data centers. This traffic is even more taxing when multiple overlay networks share a common underlay network—as is the case with tunneling technologies like VXLAN. Therefore it is desirable to reduce ARP traffic.

This can be done by allowing Virtual Tunnel End Points (VTEPs) to proxy ARP requests and reply on behalf of the remote endpoint. VTEPs snoop ARP replies, exiting the virtual network tunnel to learn the remote endpoint‘s IP to MAC mapping. The VTEP stores this in its ARP cache for the tenant VLAN.

This feature may be used even if the tenant VLAN does not have an IP interface. In that case, ARP cache entries are still learned. If an entry needs to be refreshed, the ARP request is sent with a source protocol address of all zeros. This is functionally equivalent to an ARP probe. This feature is disabled by default for configured virtual networks.

Supported Platforms

Summit X770, X670-G2, and ExtremeSwiching X870, X690 series switches.

New CLI Commands

configure vlan vlan_name suppress [arp-only |none]

configure forwarding iparpsuppression filters [per-port |per-vlan]

Changed CLI Commands

The following command's output is changed to show virtual network remote endpoints:

show iparp {ip_addr |mac | [ {vlan}vlan_name |vlan vlan_list] |permanent} {port port {vr vr_name}