Evidence Cross-8/HPoE-10G, User Manual

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Figure 7-2: The STP CIST Port Configuration
Parameter description:

Port :
The switch port number of the logical STP port.

STP Enabled :
Controls whether STP is enabled on this switch port. This field will be read only if Voice
VLAN feature is enabled. The Voice VLAN port mode will be read only if this field be
Enabled.

Path Cost :
Controls the path cost incurred by the port. The Auto setting will set the path cost as
appropriate by the physical link speed, using the 802.1D recommended values. Using the
Specific setting, a user-defined value can be entered. The path cost is used when
establishing the active topology of the network. Lower path cost ports are chosen as
forwarding ports in favor of higher path cost ports. Valid values are in the range 1 to
200000000.

Priority :
Controls the port priority. This can be used to control priority of ports having identical port
cost. (See above).

AdminEdge :
Controls whether the operEdge flag should start as set or cleared. (The initial operEdge
state when a port is initialized).

AutoEdge :
Controls whether the bridge should enable automatic edge detection on the bridge port.
This allows operEdge to be derived from whether BPDU's are received on the port or not.

Restricted Role :
If enabled, 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 vector. Such a port will be selected as an Alternate
Port after the Root Port has been selected. If set, it can cause lack of spanning tree
connectivity. It can be set by a network administrator to prevent bridges external to a core
region of the network influence the spanning tree active topology, possibly because those
bridges are not under the full control of the administrator. This feature is also known as
Root Guard.

Restricted TCN :
If enabled, causes the port not to propagate received topology change notifications and
topology changes to other ports. If set it can cause temporary loss of connectivity after
changes in a spanning tree's active topology as a result of persistently incorrect learned
station location information. It is set by a network administrator to prevent bridges external
to a core region of the network, causing address flushing in that region, possibly because
those bridges are not under the full control of the administrator or the physical link state of
the attached LANs transits frequently.

BPDU Guard :