Dell PowerConnect B-FCXs, Configuration Manual

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PowerConnect B-Series FCX Configuration Guide 261
53-1002266-01
Configuring STP related features
8
Bridge IEEE 802.1W parameters
Bridge Identifier The ID of the bridge.
Bridge Max Age The configured max age for this bridge. The default is 20.
Bridge Hello The configured hello time for this bridge.The default is 2.
Bridge FwdDly The configured forward delay time for this bridge. The default is 15.
Force-Version The configured force version value. One of the following value is
displayed:
•
0 – The bridge has been forced to operate in an STP compatibility
mode.
•
2 – The bridge has been forced to operate in an 802.1W mode.
(This is the default.)
txHoldCnt The number of BPDUs that can be transmitted per Hello Interval. The
default is 3.
Root Bridge Identifier ID of the Root bridge that is associated with this bridge
Root Path Cost The cost to reach the root bridge from this bridge. If the bridge is the root
bridge, then this parameter shows a value of zero.
Designated Bridge Identifier The bridge from where the root information was received.It can be from
the root bridge itself, but it could also be from another bridge.
Root Port The port on which the root information was received. This is the port
that is connected to the Designated Bridge.
Max Age The max age is derived from the Root port. An 802.1W-enabled bridge
uses this value, along with the hello and message age parameters to
compute the effective age of an RST BPDU.
The
message age parameter is generated by the Designated port and
transmitted in the RST BPDU. RST BPDUs transmitted by a Designated
port of the root bridge contains a message value of zero.
Effective age is the amount of time the Root port, Alternate port, or
Backup port retains the information it received from its peer Designated
port. Effective age is reset every time a port receives an RST BPDU from
its Designated port. If a Root port does not receive an RST BPDU from its
peer Designated port for a duration more than the effective age, the
Root port ages out the existing information and recomputes the
topology.
If the port is operating in 802.1D compatible mode, then max age
functionality is the same as in 802.1D (STP).
Fwd Dly The number of seconds a non-edge Designated port waits until it can
apply any of the following transitions, if the RST BPDU it receives does
not have an agreed flag:
•
Discarding state to learning state
•
Learning state to forwarding state
When a non-edge port receives the RST BPDU it goes into forwarding
state within 4 seconds or after two hello timers expire on the port.
Fwd Dly is also the number of seconds that a Root port waits for an RST
BPDU with a proposal flag before it applies the state transitions listed
above.
If the port is operating in 802.1D compatible mode, then forward delay
functionality is the same as in 802.1D (STP).
TABLE 53 CLI display of 802.1W summary (Continued)
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