D-Link DGS-3024, Руководство пользователя

Страница: 61 / 208

DGS-3024 Gigabit Ethernet Switch Manual
Figure 7- 26. STP Instance Operational Status window – Previously Configured MSTI
The following parameters may be viewed in the STP Instance Operational Status windows:
Parameter Description
Designated Root Bridge This field will show the priority and MAC address of the Root Bridge.
External Root Cost This defines a metric that indicates the relative cost of forwarding packets to the specified
port list. Port cost can be set automatically or as a metric value. The default value is
0
(auto).
•
0 (auto) - Setting 0 for the external cost will automatically set the speed for
forwarding packets to the specified port(s) in the list for optimal efficiency. Default
port cost: 100Mbps port = 200000. Gigabit port = 20000.
•
value 1-200000000 - Define a value between 1 and 200000000 to determine the
external cost. The lower the number, the greater the probability the port will be
chosen to forward packets.
Regional Root Bridge This field will show the priority and MAC address of the Regional (Internal) Root Bridge.
This MAC address should be the MAC address of the Switch.
Internal Root Cost This parameter is set to represent the relative cost of forwarding packets to specified
ports when an interface is selected within a STP instance. The default setting is
0 (auto).
There are two options:
•
0 (auto) - Selecting this parameter for the internalCost will set quickest route
automatically and optimally for an interface. The default value is derived from the
media speed of the interface.
•
value 1-2000000 - Selecting this parameter with a value in the range of 1 to
2000000 will set the quickest route when a loop occurs. A lower Internal cost
represents a quicker transmission.
Designated Bridge This field will show the priority and MAC address of the Designated Bridge. The
information shown in this table comes from a BPDU packet originating from this bridge.
Root Port This is the port on the Switch that is physically connected to the Root Bridge.
Max Age The Max Age may be set to ensure that old information does not endlessly circulate
through redundant paths in the network, preventing the effective propagation of the new
information. Set by the Root Bridge, this value will aid in determining that the Switch has
spanning tree configuration values consistent with other devices on the bridged LAN. If
the value ages out and a BPDU has still not been received from the Root Bridge, the
Switch will start sending its own BPDU to all other Switches for permission to become the
Root Bridge. If it turns out that your Switch has the lowest Bridge Identifier, it will become
the Root Bridge. The user may choose a time between 6 and 40 seconds. The default
value is 20.
47