Service Manual
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.
Figure 42. ARP Learning via ARP Request with ARP Learning via Gratuitous ARP Enabled
Whether you enable or disable ARP learning via gratuitous ARP, the system does not look up the target IP. It only updates the ARP
entry for the Layer 3 interface with the source IP of the request.
Conguring ARP Retries
In Dell Networking OS versions prior to 8.3.1.0, the number of ARP retries is set to ve and is not congurable. After ve retries, Dell
Networking OS backs o for 20 seconds before it sends a new request. Beginning with Dell Networking OS version 8.3.1.0, the
number of ARP retries is congurable.
The default backo interval remains at 20 seconds. On the device, the time between ARP resend is congurable. This timer is an
exponential backo timer. Over the specied period, the time between ARP requests increases. This time increase reduces the
potential for the system to slow down while waiting for a multitude of ARP responses.
To set and display ARP retries, use the following commands.
• Set the number of ARP retries.
CONFIGURATION mode
arp retries number
The default is 5.
The range is from 1 to 20.
• Set the exponential timer for resending unresolved ARPs.
CONFIGURATION mode
arp backoff-time
The default is 30.
The range is from 1 to 3600.
• Display all ARP entries learned via gratuitous ARP.
EXEC Privilege mode
show arp retries
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IPv4 Routing