2-2Table 2-2 Configure TCP attributesOperation Command RemarksEnter system view system-view —Configure TCP synwait timer’stimeout valuetcp timer syn-timeouttime-valueOptionalBy default, the timeout value is75 seconds.Configure TCP finwait timer’stimeout valuetcp timer fin-timeouttime-valueOptionalBy default, the timeout value is675 seconds.Configure the size of TCPreceive/send buffer tcp window window-sizeOptionalBy default, the buffer is 8kilobytes.Disabling 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.By default, Switch 4210 Family support sending ICMP redirect and destination unreachable packets.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.Table 2-3 Disable sending ICMP error packetsOperation Command RemarksEnter system view system-view —Disable sending ICMP redirects undo icmp redirect send RequiredEnabled by defaultDisable sending ICMPdestination unreachablepacketsundo icmp unreach send RequiredEnabled by defaultDisplaying and Maintaining IP Performance ConfigurationAfter the above configurations, you can execute the display command in any view to display therunning status to verify your IP performance configuration.
