2-2Task RemarksConfiguring TCP Attributes OptionalEnabling Reception and Forwarding of DirectedBroadcasts to a Directly Connected Network OptionalDisabling ICMP to Send Error Packets OptionalCanceling the System-Defined ACLs for ICMP AttackGuard OptionalConfiguring TCP AttributesTCP optional parameters that can be configured include:z synwait timer: When sending a SYN packet, TCP starts the synwait timer. If no response packetsare received before the synwait timer times out, the TCP connection is not successfully created.z finwait timer: When the TCP connection is changed into FIN_WAIT_2 state, finwait timer will bestarted. If no FIN packets are received within the timer timeout, the TCP connection will beterminated. If FIN packets are received, the TCP connection state changes to TIME_WAIT. Ifnon-FIN packets are received, the system restarts the timer from receiving the last non-FIN packet.The connection is broken after the timer expires.z Size of TCP receive/send bufferFollow these steps to configure TCP attributes:To do… Use the command… RemarksEnter system view system-view —Configure TCP synwait timer’stimeout value tcp timer syn-timeout time-value Optional75 seconds by default.Configure TCP finwait timer’stimeout value tcp timer fin-timeout time-value Optional675 seconds by default.Configure the size of TCPreceive/send buffer tcp window window-size Optional8 kilobytes by default.Enabling Reception and Forwarding of Directed Broadcasts to a Directly ConnectedNetworkDirected broadcasts refer to broadcast packets sent to a specific network. In the destination IP addressof a directed broadcast, the network ID is the ID of network where the receiving interface resides andthe host ID is all-ones. Enabling the device to receive directed broadcasts will give hackers anopportunity to attack the network, thus bringing forth great potential dangers to the network. Therefore,the reception and Forwarding of directed broadcasts to a directly connected network is disabled onS5600 series Ethernet switches by default. However, you should enable the feature when:z Using the UDP Helper function to convert broadcasts to unicasts and forward them to a specifiedserver.z Using the Wake on LAN function to forward directed broadcasts to a host on the remote network.
