LevelOne GSW-4876 - Manual (Page 126)

C HAPTER 4 | Configuring the Switch
Configuring the Spanning Tree Algorithm
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4. Set at least one of the ports in each LAG to Active initiation mode,
either at the near end or far end of the trunk.
5. Click Save.
Figure 43: LACP Port Configuration
C ONFIGURING THE S PANNING T REE A LGORITHM
The Spanning Tree Algorithm (STA) can be used to detect and disable
network loops, and to provide backup links between switches, bridges or
routers. This allows the switch to interact with other bridging devices (that
is, an STA-compliant switch, bridge or router) in your network to ensure
that only one route exists between any two stations on the network, and
provide backup links which automatically take over when a primary link
goes down.
The spanning tree algorithms supported by this switch include these
versions:
◆ STP – Spanning Tree Protocol (IEEE 802.1D)
◆ RSTP – Rapid Spanning Tree Protocol (IEEE 802.1w)
◆ MSTP – Multiple Spanning Tree Protocol (IEEE 802.1s)
STP - STP uses a distributed algorithm to select a bridging device (STP-
compliant switch, bridge or router) that serves as the root of the spanning
tree network. It selects a root port on each bridging device (except for the
root device) which incurs the lowest path cost when forwarding a packet
from that device to the root device. Then it selects a designated bridging
device from each LAN which incurs the lowest path cost when forwarding a
packet from that LAN to the root device. All ports connected to designated
bridging devices are assigned as designated ports. After determining the
lowest cost spanning tree, it enables all root ports and designated ports,
and disables all other ports. Network packets are therefore only forwarded
between root ports and designated ports, eliminating any possible network
loops.