D-Link DES-3526 - Switch - Stackable, Руководство пользователя

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DES-3526 / DES-3526DC Fast Ethernet Layer 2 Switch
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802.1d MSTP 802.1w RSTP 802.1d STP Forwarding Learning
Discarding Discarding Disabled No No
Discarding Discarding Blocking No No
Discarding Discarding Listening No No
Learning Learning Learning No Yes
Forwarding Forwarding Forwarding Yes Yes
Table 6- 1. Comparing Port States
RSTP is capable of a more rapid transition to a forwarding state - it no longer relies on timer config-
urations - RSTP compliant bridges are sensitive to feedback from other RSTP compliant bridge links.
Ports do not need to wait for the topology to stabilize before transitioning to a forwarding state. In
order to allow this rapid transition, the protocol introduces two new variables: the edge port and the
point-to-point (P2P) port.
Edge Port
The edge port is a configurable designation used for a port that is directly connected to a segment
where a loop cannot be created. An example would be a port connected directly to a single work-
station. Ports that are designated as edge ports transition to a forwarding state immediately without
going through the listening and learning states. An edge port loses its status if it receives a BPDU
packet, immediately becoming a normal spanning tree port.
P2P Port
A P2P port is also capable of rapid transition. P2P ports may be used to connect to other bridges.
Under RSTP/MSTP, all ports operating in full-duplex mode are considered to be P2P ports, unless
manually overridden through configuration.
802.1d/802.1w/802.1s Compatibility
MSTP or RSTP can interoperate with legacy equipment and is capable of automatically adjusting
BPDU packets to 802.1d format when necessary. However, any segment using 802.1d STP will not
benefit from the rapid transition and rapid topology change detection of MSTP or RSTP. The protocol
also provides for a variable used for migration in the event that legacy equipment on a segment is
updated to use RSTP or MSTP.
The Spanning Tree Protocol (STP) operates on two levels:
1. On the switch level, the settings are globally implemented.
2. On the port level, the settings are implemented on a per user-defined group of ports basis.
STP Bridge Global Settings
To open the following window, open the Spanning Tree folder in the Configuration menu and click
the STP Bridge Global Settings link.