LevelOne GEP-1070, Руководство пользователя

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cost for all ports on a switch are the same, the port with the highest priority (i.e., lowest
value) will be configured as an active link in the Spanning Tree. This makes a port with
higher priority less likely to be blocked if the Spanning Tree Algorithm is detecting network
loops. Where more than one port is assigned the highest priority, the port with lowest
numeric identifier will be enabled. (Range: 0-240, in steps of 16; Default: 128)
◆
Admin Edge (Fast Forwarding)
– You can enable this option if an interface is attached to
a LAN segment that is at the end of a bridged LAN or to an end node. Since end nodes
cannot cause forwarding loops, they can pass directly through to the spanning tree
forwarding state. Specifying edge ports provides quicker convergence for devices such as
workstations or servers, retains the current forwarding database to reduce the amount of
frame flooding required to rebuild address tables during reconfiguration events, does not
cause the spanning tree to initiate reconfiguration when the interface changes state, and
also overcomes other STA-related timeout problems. However, remember that this feature
should only be enabled for ports connected to an end-node device. (Default: Edge)
◆
Auto Edge
– Controls whether automatic edge detection is enabled on a bridge port.
When enabled, the bridge can determine that a port is at the edge of the network if no
BPDU's are received on the port. (Default: Enabled)
◆
Restricted Role
– If enabled, this causes the port not to be selected as Root Port for the
CIST or any MSTI, even if it has the best spanning tree priority. Such a port will be
selected as an Alternate Port after the Root Port has been selected. If set, this can cause a
lack of spanning tree connectivity. It can be set by a network administrator to prevent
bridges external to a core region of the network influencing the spanning tree active
topology, possibly because those bridges are not under the full control of the administrator.
This feature is also know as Root Guard.
◆
Restricted TCN
– If enabled, this causes the port not to propagate received topology
change notifications and topology changes to other ports. TCN messages can cause
temporary loss of connectivit
y after changes in a spanning tree’s active topology as a result
of persistent incorrectly learned station location information. TCN messages can be
restricted by a network administrator to prevent bridges external to a core region of the
network from causing address flushing in that region, possibly because those bridges are
not under the full control of the administrator or the physical link state for the attached
LANs transitions frequently.
◆
BPDU Guard
– This feature protects ports from receiving BPDUs. It can prevent loops by
shutting down an port when a BPDU is received instead of putting it into the spanning tree
discarding state. The BPDU guard feature provides a secure response to invalid
configurations because an administrator must manually enable the port. (Default: Disabled)
If enabled, the port will disable itself upon receiving valid BPDU's. Contrary to the similar
bridge setting, the port Edge status does not affect this setting. A port entering error-disabled
state due to this setting is subject to the bridge Port Error Recovery setting as well (see
"Configuring Bridge Settings for STA" on page 118).