2-3Disabling ICMP to Send Error PacketsSending error packets is a major function of ICMP protocol. In case of network abnormalities, ICMPpackets are usually sent by the network or transport layer protocols to notify corresponding devices soas to facilitate control and management.Although sending ICMP error packets facilitate control and management, it still has the followingdisadvantages:z Sending a lot of ICMP packets will increase network traffic.z If receiving a lot of malicious packets that cause it to send ICMP error packets, the device’sperformance will be reduced.z As the ICMP redirection function increases the routing table size of a host, the host’s performancewill be reduced if its routing table becomes very large.z If a host sends malicious ICMP destination unreachable packets, end users may be affected.You can disable the device from sending such ICMP error packets for reducing network traffic andpreventing malicious attacks.Follow these steps to disable sending ICMP error packets:To do… Use the command… RemarksEnter system view system-view —Disable sending ICMP redirects undo icmp redirect send RequiredEnabled by default.Disable sending ICMPdestination unreachablepacketsundo icmp unreach send RequiredEnabled by default.Displaying and Maintaining IP Performance ConfigurationTo do… Use the command… RemarksDisplay TCP connection status display tcp statusDisplay TCP connection statistics display tcp statisticsDisplay UDP traffic statistics display udp statisticsDisplay IP traffic statistics display ip statisticsDisplay ICMP traffic statistics display icmp statisticsDisplay the current socket information of thesystemdisplay ip socket[ socktype sock-type ][ task-id socket-id ]Display the forwarding information base (FIB)entries display fibDisplay the FIB entries matching thedestination IP addressdisplay fib ip_address1[ { mask1 | mask-length1 }[ ip_address2 { mask2 |mask-length2 } | longer ] |longer ]Display the FIB entries filtering through aspecific ACL display fib acl numberAvailable in anyview
