Configuring Rate Limiting on ARP Miss Messages based on Source IP Addresses
Context
If a user host sends a large number of IP packets with unresolvable destination IP addresses to a network device (the device has a route to the destination IP address of a packet but has no ARP entry matching the next hop of the route), the device generates a large number of ARP Miss messages. IP packets triggering ARP Miss messages are sent to the device for processing. The device generates a large number of temporary ARP entries and sends many ARP Request packets to the network, consuming a large number of CPU and bandwidth resources.
If the number of ARP Miss messages triggered by IP packets from a source IP address per second exceeds the limit, the device considers that an attack has been initiated from the source IP address.
The administrator can set the maximum number of ARP Miss messages that the device can process within a specified duration based on the actual network environment, protecting the system resources and ensuring proper running of other services.
Perform the following steps on the gateway.
Procedure
- Run system-view
The system view is displayed.
- Configure rate limiting on ARP Miss messages based on source
IP addresses.
- Run arp miss anti-attack rate-limit source-ip maximum maximum
The maximum rate of ARP Miss messages triggered by IP packets from any source IP address is set.
- Run arp miss anti-attack rate-limit source-ip ip-address [ mask { mask-length | mask } ] maximum maximum
The maximum rate of ARP Miss messages triggered by IP packets from a specified source IP address is set.
When the preceding configurations are both performed, the maximum rate set using the arp miss anti-attack rate-limit source-ip ip-address [ mask { mask-length | mask } ] maximum maximum command takes effect on ARP Miss messages triggered IP packets from the specified source IP address, and the maximum rate set using the arp miss anti-attack rate-limit source-ip maximum maximum command takes effect on ARP Miss messages triggered by IP packets from other source IP addresses.
If the maximum rate of ARP Miss messages is set to 0, the rate of ARP Miss messages is not limited based on source IP addresses. By default, the device accepts a maximum of 50 ARP Miss messages triggered by IP packets from the same source IP address per second.
- Run arp miss anti-attack rate-limit source-ip maximum maximum
- Run commit
The configuration is committed.