No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search


To have a better experience, please upgrade your IE browser.


Configuration Guide - Security

S7700 and S9700 V200R011C10

This document describes the configurations of Security, including ACL, reflective ACL, local attack defense, MFF, attack defense, traffic suppression and storm control, ARP security, port security, DHCP snooping, ND snooping, PPPoE+, IPSG, SAVI, URPF, keychain, separating the management plane from the service plane, security risks.
Rate and give feedback:
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
Defense Against ARP Flood Attacks

Defense Against ARP Flood Attacks

As shown in Figure 7-8, user hosts connect to the gateway through SwitchA and SwitchB. If a large number of ARP packets are broadcast on the network, the gateway cannot process other services due to CPU overload. Processing too many ARP packets will occupy considerable bandwidth, thus leading to network congestion and affecting network communication.

Figure 7-8  Defending against ARP flood attacks

To avoid the preceding problems, deploy ARP flood defense functions on the gateway, including rate limit on ARP packets, rate limit on ARP Miss messages, gratuitous ARP packet discarding, strict ARP learning, and ARP entry limit.

  • After rate limit on ARP packets is deployed, the gateway collects statistics on received ARP packets. If the number of ARP packets received within a specified period exceeds the threshold (the maximum number of ARP packets), the gateway discards the excess ARP packets to prevent CPU overload.

  • After rate limit on ARP Miss messages is deployed, the gateway collects statistics on ARP Miss messages. If the number of ARP Miss messages generated within a specified period exceeds the threshold (the maximum number of ARP Miss messages), the gateway discards the IP packets triggering the excess ARP Miss messages. This prevents CPU overload when the gateway processes a large number of IP packets with unresolvable IP addresses.

  • After gratuitous ARP packet discarding is deployed, the gateway discards gratuitous ARP packets, reducing CPU load.

  • After strict ARP learning is deployed, the gateway learns only the ARP Reply packets in response to the ARP Request packets that it has sent. This action prevents ARP entries on the gateway from being exhausted when the gateway processes many ARP packets.

  • After ARP entry limit is deployed, the gateway limits the number of ARP entries dynamically learned by each interface. When the number of the ARP entries dynamically learned by an interface reaches the maximum number, no more dynamic entries can be added. This prevents ARP entries from being exhausted when a host connected to the interface attacks the gateway.

Updated: 2019-10-18

Document ID: EDOC1000178319

Views: 151963

Downloads: 84

Average rating:
This Document Applies to these Products
Related Documents
Related Version
Previous Next