IPv6 Neighbor Discovery Suppression

In a data center fabric, you can suppress Neighbor Discovery (ND) to help reduce ND control traffic.

Note

Note

ND suppression is supported on VLANs and bridge domains.

By default, ND 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 ND cache.
  2. The device broadcasts an ND request throughout the IP fabric.
When ND 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 ND cache.
  2. The device broadcasts an ND 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 ND on the respective VLANs or BDs to prevent ND broadcast across the network.
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