Cabletron Systems SPECTRUM, Руководство пользователя

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The Spanning Tree Protocol Window 6-23
Using the 7C0x SmartSwitch Bridge View
Hello Time
Indicates, in seconds, the length of time the Root Bridge, or bridge attempting to
become the Root, waits before resending a Configuration BPDU. The Root Bridge
determines the Hello Time.
Priority
The Spanning Tree Algorithm assigns each bridge a unique identifier, which is
derived from the individual port’s MAC address and its priority as determined
by the Spanning Tree Algorithm or your setting. The bridge with the lowest value
of bridge identifier is selected as the Root. A lower priority number indicates a
higher priority; a higher priority enhances a bridge’s chance of being selected as
the Root.
Acceptable values range from 0-FFFF and can be edited to change the network
topology, if needed. The default is 8000.
Root Port
The port identifier (i.e., the physical index number) for the port that provides the
lowest cost path to the Root Bridge. The Root Port field displays 0 if this bridging
device is the Root Bridge.
Root Cost
Indicates the cost of the data path from this bridge to the Root Bridge. Each port
on each bridge adds a “cost” to a particular path that a frame must travel. For
example, if each port in a particular path has a Path Cost of 1, the Root Cost
would be a count of the number of bridges along the path. This field will read 0 if
an interface on the 7C0x SmartSwitch is the Root Bridge. See Changing a Port’s
STA Parameters
, page 6-27 , to find out how to set a port’s Path Cost.
Hold Time
The minimum time, in seconds, that can elapse between the transmission of
Configuration BPDUs. The Hold Time ensures that Configuration BPDUs are not
transmitted too frequently through any bridge port. Receipt of a Configuration
BPDU starts the Hold Time count at a device. If the Hold Time expires, the port
invokes the Transmit Configuration BPDU procedure, which sends configuration
change information to the Root. The Hold Time is a fixed value, as specified by
the IEEE 802.1d specification.
NOTE
The values for the Forward Delay, Max Age, Hold Time, and Hello Time fields are stored
within the MIB in units of hundredths of a second rather than seconds; your Cabletron
management application converts hundredths of a second to seconds for display purposes.
You can use any SNMP Set Request tool to edit the values for these three fields; just
remember that you must enter your values in hundredths of seconds, rather than in
seconds.