Run the display arp anti-attack configuration arpmiss-rate-limit command on the Router to view the configuration of ARP Miss suppression.

You can change the rate limit for ARP Miss messages by running the arp-miss speed-limit source-ip command in the system view. When the rate of ARP Miss messages triggered by packets from the specified IP address exceeds the limit, the Router discards the packets sent from the IP address.

By default, ARP Miss suppression is enabled, and the maximum rate of ARP Miss messages is limited to 5 pps.

If not, the Router limits the rate of the ARP Miss messages based on the limit set in the command without a source IP address specified. If so, the Router limits the rate of ARP Miss messages based on the rate limit configured in this command.

If a source IP address is specified in the ARP Miss suppression command, the Router checks whether the specified IP address is the source address of the received IP packets.

Run the display arp anti-attack configuration arpmiss-speed-limit command to view the configuration of ARP Miss suppression.

Capture packets on the user-side interface and check the source addresses of IP packets.

If the CPU usage of the ARP task is high, the Router fails to send ARP requests and generates ARP Miss messages.

Generally, the possible causes are: the Router fails to send ARP requests, the ARP requests are discarded during transmission, or no ARP reply is received. If the MAC address in an ARP entry is in Incomplete state, the Router fails to learn the ARP entry. Run the display arp command to view the learned ARP entries.

Router security scan