In the request, the host uses its own IP address in the Sender Protocol Address and Target Protocol Address fields.Enabling ARP Learning via Gratuitous ARPTo enable ARP learning via gratuitous ARP, use the following command.• Enable ARP learning via gratuitous ARP.CONFIGURATION modearp learn-enableARP Learning via ARP RequestIn Dell Networking OS versions prior to 8.3.1.0, Dell Networking OS learns via ARP requests only if the target IP specified in the packetmatches the IP address of the receiving router interface. This is the case when a host is attempting to resolve the gateway address.If the target IP does not match the incoming interface, the packet is dropped. If there is an existing entry for the requesting host, it isupdated.Figure 51. ARP Learning via ARP RequestBeginning with Dell Networking OS version 8.3.1.0, when you enable ARP learning via gratuitous ARP, the system installs a new ARP entry,or updates an existing entry for all received ARP requests.Figure 52. ARP Learning via ARP Request with ARP Learning via Gratuitous ARP EnabledWhether you enable or disable ARP learning via gratuitous ARP, the system does not look up the target IP. It only updates the ARP entryfor the Layer 3 interface with the source IP of the request.IPv4 Routing 423
