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Command Line Interface
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Command Usage
• The ARP cache is used to map 32-bit IP addresses into 48-bit hardware (i.e.,
Media Access Control) addresses. This cache includes entries for hosts and
other routers on local network interfaces defined on this router.
• The maximum number of static entries allowed in the ARP cache is 128.
• You may need to enter a static entry in the cache if there is no response to an
ARP broadcast message. For example, some applications may not respond
to ARP requests or the response arrives too late, causing network operations
to time out.
Example
Related Commands
clear arp-cache
show arp
arp-timeout
This command sets the aging time for dynamic entries in the Address Resolution
Protocol (ARP) cache. Use the no form to restore the default.
Syntax
arp-timeout seconds
no arp-timeout
seconds - The time a dynamic entry remains in the ARP cache.
(Range: 300-86400; 86400 is one day)
Default Setting
1200 seconds (20 minutes)
Command Mode
Global Configuration
Command Usage
Use the show arp command to display the current cache timeout value.
Example
This example sets the ARP cache timeout for 15 minutes (i.e., 900 seconds).
Console(config)#arp 10.1.0.19 01-02-03-04-05-06
Console(config)#
Console(config)#arp-timeout 900
Console(config)#