3Com Switch 8800 Configuration Guide Chapter 12 ARP Configuration12-412.3 Displaying and Debugging ARPAfter the above configuration, execute the display command in any view to display therunning of the ARP configuration, and to verify the effect of the configuration.Execute the reset command in user view to clear ARP mapping table. Execute thedebugging command in user view to debug ARP configuration.Table 12-4 Display and debug ARPOperation CommandDisplay ARP mapping table display arp [ ip-address | [ dynamic | static ][ | { begin | include | exclude } text ] ]Display the current setting of thedynamic ARP aging timer display arp timer agingReset ARP mapping tablereset arp [ dynamic | static | interface{ interface_type interface_num |interface_name } | all ]Enable ARP information debugging debugging arp { error | info | packet }Disable ARP informationdebugging undo debugging arp { error | info | packet }12.4 Enabling/Disabling the Scheme of Preventing Attackfrom Packets12.4.1 Introduction to the Scheme of Preventing Attack from PacketsA scheme of preventing attack from packets is designed against some typical attackmodes on the 8800 series switches. The scheme can prevent attacks from IP, ARP,802.1x and unknown multicast packets.z IP packet attack: Means that a Switch 8800 receives too many IP packets whosedestination addresses and VLAN port address are in the same segment. Theswitch has no corresponding forwarding entries for the packets, therefore they aresent to the CPU, occupying lots of CPU resource and even affecting normal dataforwarding.z ARP packet attack: Means that a Switch 8800 receives lots of ARP requestpackets with the same or similar source media access control (MAC) addresses,affecting normal ARP learning.z 802.1x packet attack: Means that a Switch 8800 receives lots of 802.1xauthentication packets with the same or similar source MAC addresses,consequently occupying the CPU resources.Perform the following configuration in system view.
