Industrial Ethernet Switch User Manual
3onedata proprietary and confidential
17
Copyright © 3onedata Co., Ltd.
There are many reasons to cause broadcast storm. For example: a redundant or
incorrect connect among switches.
If enable storm suppression, it can stop the attack. Our device can detect 3 kinds of
broadcast messages according to the type of broadcast storm.
Broadcast packets: data frame of the destination address of FF-FF-FF-FF-FF-FF
Multicast packets: destination address is XX-XX-XX-XX-XX-XX data frames, second x
is odd numbers such as 1, 3, 5, 7, 9, b, d, and f, x represents any digit.
Unicast: unicast is the term used to describe communication where a piece of
information is sent from one point to another point. In this case there is just one
sender, and one receiver.
Destination lookup failure frame: the MAC address of this data frame doesn't exist in
inside index. It needs to transmit to all the ports, including unicast and multicast flow.
Notes:
The maximum length of Ethernet data frames is 1518 bytes, and each 64Kb of data
communication includes about 6 Ethernet data frames with 1518-byte.
The minimum length of Ethernet data frames is 64 bytes. Each 64 Kb of data
communication includes about 128 Ethernet data frames with 64-byte.
In the network the broadcast packets are more than 800packet/s, the network delay is
obvious.
The recommended setting is 3% based on the above theory.
Please be caution to use MAC control frame and destination lookup failure frame,
disabling IGMP Snooping will have impact on the transmission of the multicast.
