We had a question at TSS, during our Aruba Fabric Composer Lab workshop, which I'm following up on relating to ARP and the process to reduce the number of ARP requests propagating across the underlay when we are using VXLAN encapsulation with EVPN..
The 'arp suppression' feature assists in avoiding flooding of arp requests for known end points across the network with EVPN whereby the switch responds locally to arp requests instead of flooding across the network.
ARP suppression
- The EVPN arp suppression command enables ARP suppression for EVPN-VXLAN globally across all Layer 2 VNIs configured on the VTEP.
- If the target address is present in the neighbor cache, the switch (local) responds to the broadcast or unicast ARP request instead of forwarding the request over the VXLAN.
- If the target IP/MAC is not present, the switch forwards arp request over the VXLAN data plane for neighbor resolution.
- ARP suppression is disabled by default but is enabled as part of the Aruba Fabric Composer EVPN workflow.
The arp suppression feature assists in avoiding flooding of arp requests for known end points across the network. ( similar in objective to the 'arp-snooping' feature from Cisco.
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Steve Bartlett
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