Black Box LPB5028A, Руководство пользователя

Страница: 69 / 244

724-746-5500 | blackbox.com
Page 69
Chapter 5: Configuration
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, elimi-
nating any possible network loops.
Figure 5-16. Spanning Tree example.
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.
5.4.1 Bridge Settings
The section describes that 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.
Web Interface
To configure the Spanning Tree Bridge Settings parameters in the web interface:
1. Click Configuration, Spanning Tree, Bridge Settings.
2. Scoll to select the parameters and write down available value of parameters in blank field in Basic Settings.
3. Enable or disable the parameters in a blank field in Advanced settings.
4. Click Apply to save the setting.
5. To cancel the setting, click the Reset button. It will revert to previously saved values.