When processing a large number of ARP packets with fixed source IP addresses, the CPU of a device is overloaded and cannot process other services.
To prevent this problem, configure the gateway to rate-limit ARP packets based on source IP addresses. The gateway collects statistics on ARP packets from a specified source IP address. If the number of ARP packets received in one second from the specified source IP address exceeds the threshold, the device discards the excess ARP packets.
The system view is displayed.
Run arp speed-limit source-ip maximum maximum
The maximum rate of ARP packets from any source IP address is set.
Run arp speed-limit source-ip ip-address maximum maximum
The maximum rate of ARP packets from the specified source IP address is set.
When both the preceding commands are executed, the maximum rate set using the arp speed-limit source-ip ip-address maximum maximum command takes effect on ARP packets from the specified source IP address, and the maximum rate set using the arp speed-limit source-ip maximum maximum command takes effect on ARP packets from other source IP addresses.
By default, the device allows a maximum of 30 ARP packets from the same source IP address to pass through per second.
After the optimized ARP reply function (disabled by default) is enabled using the undo arp optimized-reply disable command, rate limiting on ARP packets based on the source IP address does not take effect.