https://vlan51.com/tags/arp/Recent content in Arp on vlan51Hugoen-gbMon, 01 Jan 2024 00:00:00 +0000https://vlan51.com/aruba-provision/static-arp-nlb-multicast/Mon, 01 Jan 2024 00:00:00 +0000https://vlan51.com/aruba-provision/static-arp-nlb-multicast/<p>Microsoft NLB in multicast mode causes switches to flood traffic to all ports because the multicast MAC address is never seen as a source — the switch cannot learn which port the cluster is on and treats it as an unknown destination.</p> <p>HPE Aruba ArubaOS-Switch does not have a direct static MAC/ARP entry feature like Cisco, but <code>ip arp-mcast-replies</code> combined with IGMP resolves the flooding.</p> <h2 id="hpe-aruba-solution">HPE Aruba solution <a class="anchor" href="#hpe-aruba-solution" aria-label="Link to this section">#</a></h2> <div class="code"> <div class="code-bar"><span>cli</span><button class="copy" type="button" aria-label="Copy to clipboard">Copy</button></div><pre><code>ip arp-mcast-replies</code></pre></div> <p>Enable IGMP on the NLB client VLAN, and ensure NLB is set to <strong>multicast</strong> cluster operation mode:</p>