Planet GS-5220 Series, Руководство пользователя, Страница: 239 / 568

User’s Manual of GS-5220 LCD Series
239
• 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 If enabled, causes the port to disable itself upon receiving valid BPDU's.
Contrary to the similar bridge setting, the port
Edge status does not
effect this setting.
A port entering error-disabled state due to this setting is subject to the
bridge Port Error Recovery setting as well.
• Point-to-point Controls whether the port connects to a point-to-point LAN rather than
a shared medium. This can be automatically determined, or forced
either true or false. Transitions to the forwarding state is faster for
point-to-point LANs than for shared media.