Industrial Managed
Ethernet Switch – EH9711
User Manual
Page
88
of
223
LACP packets along the configured links. In passive mode however, LACP port acts as “speak when spoken to”, and therefore
can be used as a way of controlling accidental loops (as long as the other device is in active mode).
Figure 2.72 shows the LACP System Configuration webpage. It allows the user to configure the System Priority and LACP
System Configuration. Table 2.59 summarizes the descriptions of LACP Aggregation Configuration.
Figure 2.72 Webpage to Configure LACP Aggregation
Table 2.59 Descriptions of LACP Aggregation Configuration
Label
Description
Factory
Default
Port
The switch port number.
-
LACP
Show whether LACP is currently enabled on this switch port.
No
Timeout
The
Timeout
controls the period between BPDU
transmissions.
Fast
will transmit LACP packets each second,
while
Slow
will wait for 30 seconds before sending a LACP packet.
Fast
Click
Save
button to save changes. Click
Reset
button to undo any changes made locally and revert to previously saved
values.
2.7
Spanning Tree
IEEE 802.1D Standard spanning tree functionality is supported by Atop’s EH9711 managed switches.
Spanning Tree Protocol (STP)
provides a function to prevent switching loops and broadcast radiation at the OSI layer 2. A
switching loop occurs in a network when there are multiple connections or redundant paths between two network switches or
at least two ports are connected on both sides of the two network switches. The switching loop can create a broadcast radiation,
which is the accumulation of broadcast and multicast traffics in a computer network. As broadcast and multicast messages are
forwarded by bridges/switches to every port, the bridges/switches will repeatedly rebroadcast the broadcast messages, and this
accumulation of traffic can flood the network. STP creates a spanning tree topology and disables those links of the network
that are not part of the spanning tree, which leaves only a single active path between two nodes. This function can avoid
flooding and increase network efficiency. Therefore, Atop’s managed switches deploy spanning tree as a tool when the users
set up connection or port redundancy or fault-tolerance in their network.
RSTP (Rapid Spanning Tree Protocol)
, IEEE 802.1W, is also supported in Atop’s managed switches. It is an evolution of
the STP, but it is still backwards compatible with standard STP. RSTP has the advantage over the STP. When there is a topology
change such as link failure in the network, the RSTP will converge significantly faster to a new spanning tree topology. RSTP
improves convergence on point-to-point links by reducing the Max-Age time to 3 times Hello interval, removing the STP
listening state, and exchanging a handshake between two switches to quickly transition the port to forwarding state.
