ARP Suppression

Note

Note

ARP suppression is supported on VLANs and bridge domains.

By default, ARP is not suppressed, which can lead to excess control traffic.

  1. A device needs to forward traffic to an IP address, but the corresponding MAC address is not in its ARP cache.
  2. The device broadcasts an ARP request throughout the IP fabric.
When ARP is suppressed, excess control traffic is reduced.
  1. A device needs to forward traffic to an IP address, but the corresponding MAC address is not in its ARP cache.
  2. The device broadcasts an ARP request.
  3. The leaf BGP EVPN control plane intercepts the request and looks for a match in its local cache.
    • If there is a match, the control plane responds only to the device.
    • If there is no match, the leaf control plane broadcasts the request to the entire IP fabric.
Tip

Tip

When the static anycast gateway feature is enabled in an IP fabric, suppress ARP on the respective VLANs or BDs to prevent ARP broadcast across the network.
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