When a Layer 2 Ethernet interface on a switch receives broadcast, multicast, or unknown unicast packets, the switch forwards the packets to other Layer 2 Ethernet interfaces in the same VLAN if the switch cannot determine the outbound interfaces based on the destination MAC addresses of these packets. In this case, a broadcast storm may occur, and the forwarding performance of the switch deteriorates.
Traffic suppression and storm control can control these packets and prevent broadcast storms.
Traffic suppression limits traffic based on the configured threshold, and storm control blocks traffic by shutting down interfaces.
On a tree network with a downstream user network, storm control is recommended to prevent storms on the user network from spreading over the entire network. On internal connection interfaces of a network, traffic suppression is recommended to reduce the network-wide service impact of broadcast storms caused by loops.
Configure traffic suppression on an interface.
To limit the rate of broadcast, multicast, or unknown unicast packets on an interface and prevent broadcast storms, configure traffic suppression for these types of packets on the interface.
<HUAWEI> system-view [HUAWEI] interface gigabitethernet 1/0/1 [HUAWEI-GigabitEthernet1/0/1] broadcast-suppression 30 [HUAWEI-GigabitEthernet1/0/1] multicast-suppression 30 [HUAWEI-GigabitEthernet1/0/1] unicast-suppression 30 [HUAWEI-GigabitEthernet1/0/1] quit
Configure storm control.
To limit the rate of broadcast, multicast, or unknown unicast packets on an interface and prevent heavy traffic on the switch, configure storm control for these types of packets on the interface. When detecting that the traffic volume exceeds the configured threshold, the switch punishes the interface to isolate impact of the storm.
<HUAWEI> system-view [HUAWEI] interface gigabitethernet 1/0/1 [HUAWEI-GigabitEthernet1/0/1] storm-control broadcast min-rate 5000 max-rate 8000 [HUAWEI-GigabitEthernet1/0/1] storm-control action error-down [HUAWEI-GigabitEthernet1/0/1] storm-control enable trap