Configuration Guide Configuring ARP
Global configuration mode
If a large number of unresolved entries exist in the ARP cache table and remain in the table after a while, it is
recommended to use this command to limit the number of unresolved ARP entries.
 Configuring the Maximum Number of ARP Entries on an Interface
arp cache interface-limit limit
limit: Indicates the maximum number of ARP entries that can be learned on an interface, including
configured ARP entries and dynamically learned ARP entries. The value ranges from 0 to the ARP entry
capacity supported by the device. 0 indicates no limit on this number.
Interface configuration mode
Limiting the number of ARP entries on an interface can prevent malicious ARP attacks from generating
excessive ARP entries on the device and occupying entry resources. The configured value must be equal to
or greater than the number of the ARP entries learned by the interface. Otherwise, the configuration does
not take effect. The configuration is subject to the ARP entry capacity supported by the device.
Configuration
Example
For the network topology, see Figure 2-1.
 Set the ARP timeout to 60 seconds on port GigabitEthernet 0/1.
 Set the maximum number of learned ARP entries to 300 on port GigabitEthernet 0/1.
 Set the ARP request retransmission interval to 3 seconds.
 Set the ARP request retransmission times to 4.
 Set the maximum number of unresolved ARP entries to 4,096.
Ruijie(config)#interface gigabitEthernet 0/1
Ruijie(config-if-GigabitEthernet 0/1)#arp timeout 60
Ruijie(config-if-GigabitEthernet 0/1)#arp cache interface-limit 300
Ruijie(config-if-GigabitEthernet 0/1)#exit
Ruijie(config)#arp retry interval 3
Ruijie(config)#arp retry times 4
Ruijie(config)#arp unresolve 4096
 Run the show arp timeout command to display the timeout of the interface.
 Run the show running-config command to display the ARP request retransmission interval and
times, maximum number of unresolved ARP entries, maximum number of ARP entries on the interface,
and maximum number of ARP entries on the board.
Ruijie#show arp timeout
Interface arp timeout(sec)
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