Dell S4820T, Configuration Manual

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Beginning with Dell Networking OS version 8.3.1.0, when a gratuitous ARP is received, Dell Networking
OS installs an ARP entry on all three CPUs.
Enabling ARP Learning via Gratuitous ARP
To enable ARP learning via gratuitous ARP, use the following command.
• Enable ARP learning via gratuitous ARP.
CONFIGURATION mode
arp learn-enable
ARP Learning via ARP Request
In 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 packet matches 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 is updated.
Figure 47. ARP Learning via ARP Request
Beginning 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.
IPv4 Routing
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