3com DUA1750-2BAA01 Manual De Usuario

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3Com Switch 8800 Configuration Guide 
Chapter 12  ARP Configuration
 
12-4 
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 
Operation 
Command 
Display ARP mapping table 
display arp [ ip-address | [ dynamic | static ] 
[ | { begin | include | exclude } text ] ] 
Display the current setting of the 
dynamic ARP aging timer 
display arp timer aging 
Reset ARP mapping table 
reset  arp [ dynamic | static  | interface 
interface_type 
interface_num 
| 
interface_name } | all ] 
Enable ARP information debugging
debugging arp error | info | packet } 
Disable ARP information 
debugging 
undo debugging arp error | info | packet }
 
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.