724-746-5500 | blackbox.com
724-746-5500 | blackbox.com
Page 63
LGB5028A User‘s Manual
Chapter 6: Configuration
Parameter Description
Port: The switch port number.
LACP Received: Shows how many LACP frames have been received at each port.
LACP Transmitted: Shows how many LACP frames have been sent from each port.
Discarded: Shows how many unknown or illegal LACP frames have been discarded at each port.
Auto-refresh: Check this box to auto-refresh to refresh the information automatically.
Upper right icon (Refresh, Clear): Click on the “Refresh” button to refresh the LACP port statistics information manually or click on
the “Clear” button to clear all entries.
6.4 Spanning Tree
The Spanning Tree Protocol (STP) 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 STP-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 that automatically take over when a primary link goes down.
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
that 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.
Figure 6-16. Spanning tree.
Once a stable network topology has been established, all bridges listen for “Hello BPDUs” (Bridge Protocol Data Units)
transmitted from the root bridge. If a bridge does not get a Hello BPDU after a predefined interval (Maximum Age), the bridge
assumes that the link to the root bridge is down. This bridge will then initiate negotiations with other bridges to reconfigure the
network to reestablish a valid network topology.
6.4.1 Bridge Settings
The section describes how to configure the spanning tree bridge and STP system settings. It allows you to configure STP
system settings that are used by all STP bridge instances in the switch.
Web Interface
To configure the Spanning Tree Bridge Settings parameters in the Web interface:
1. Click “Configuration,” “Spanning Tree,” “Bridge Settings”
2. Scroll to select the parameters and write down available value of parameters in blank field in Basic Settings.
3. Enable or disable the parameters and write down available value of parameters in the blank field in Advanced settings.
