One day switch’s CPU rises instantly and cause network interruption of the network. Through the traffic log, we find that there is ICMP dos attack to the switch which cause the instant increase to switch’s CPU. Customer wants us to solve this problem so that when DOS attack is detected, it would affect the whole network.
CPU defending feature is added to S5720 to handle DOS attack.
cpu-defend policy io-board // creates an attack defense policy and displays the attack defense policy view.
auto-defend enable // enable automatic attack source tracing.
auto-defend attack-packet sample 5 // sets the packet sampling ratio for attack source tracing. The value is an integer that ranges from 1 to 1024.
auto-defend threshold 30 // sets the checking threshold for attack source tracing. The value is an integer that ranges from 1 to 65535, in pps.
auto-port-defend aging-time // configures the aging time for port attack defense. The value is an integer that ranges from 30 to 86400, and must be a multiple of 10. The unit is second.
undo auto-defend trace-type source-portvlan // deletes an attack source tracing mode.
undo auto-defend protocol xx // By default, the device traces sources of 8021X, ARP, DHCP, ICMP, IGMP, TCP, Telnet in attack source tracing. You can choice which you need.
auto-defend action deny // Discards packets sent from an attack source.
auto-defend whitelist 1 interface GigabitEthernet x/x/x //uplink port add to whitelist
auto-defend whitelist 2 interface GigabitEthernet x/x/x //uplink port add to whitelist
cpu-defend-policy io-board global // the attack defense policy is applied to the device