Displaying And Debugging Arp; Enabling/Disabling The Scheme Of Preventing Attack From Packets; Introduction To The Scheme Of Preventing Attack From Packets - 3Com 8800 Configuration Manual

3Com Switch 8800 Configuration Guide

12.3 Displaying and Debugging ARP

After the above configuration, execute the display command in any view to display the
running 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 the
debugging command in user view to debug ARP configuration.
Table 12-4 Display and debug ARP
Display ARP mapping table
Display the current setting of the
dynamic ARP aging timer
Reset ARP mapping table
Enable ARP information debugging
Disable
debugging
12.4 Enabling/Disabling the Scheme of Preventing Attack
from Packets

12.4.1 Introduction to the Scheme of Preventing Attack from Packets

A scheme of preventing attack from packets is designed against some typical attack
modes on the 8800 series switches. The scheme can prevent attacks from IP, ARP,
802.1x and unknown multicast packets.
IP packet attack: Means that a Switch 8800 receives too many IP packets whose
destination addresses and VLAN port address are in the same segment. The
switch has no corresponding forwarding entries for the packets, therefore they are
sent to the CPU, occupying lots of CPU resource and even affecting normal data
forwarding.
ARP packet attack: Means that a Switch 8800 receives lots of ARP request
packets with the same or similar source media access control (MAC) addresses,
affecting normal ARP learning.
802.1x packet attack: Means that a Switch 8800 receives lots of 802.1x
authentication packets with the same or similar source MAC addresses,
consequently occupying the CPU resources.
Perform the following configuration in system view.
Operation
ARP information
12-4
Chapter 12 ARP Configuration
Command
display arp [ ip-address | [ dynamic | static ]
[ | { begin | include | exclude } text ] ]
display arp timer aging
reset arp [ dynamic | static | interface
{ interface_type
interface_name } | all ]
debugging arp { error | info | packet }
undo debugging arp { error | info | packet }
interface_num |