125
■ Options: 0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, 240
◆
Forward Delay
– The maximum time (in seconds) this device will wait before changing
states (i.e., discarding to learning to forwarding). This delay is required because every
device must receive information about topology changes before it starts to forward frames.
In addition, each port needs time to listen for conflicting information that would make it
return to a discarding state; otherwise, temporary data loops might result.
Minimum: The higher of 4 or [(Max. Message Age / 2) + 1]
Maximum: 30
Default: 15
◆
Max Age
– The maximum time (in seconds) a device can wait without receiving a
configuration message before attempting to reconfigure. All device ports (except for
designated ports) should receive configuration messages at regular intervals. Any port that
ages out STA information (provided in the last configuration message) becomes the
designated port for the attached LAN. If it is a root port, a new root port is selected from
among the device ports attached to the network. (Note that references to “ports” in this
section mean “interfaces,” which includes both ports and trunks.)
Minimum: The higher of 6 or [2 x (Hello Time + 1)]
Maximum: The lower of 40 or [2 x (Forward Delay - 1)]
Default: 20
◆
Transmit Hold Count
– The number of BPDU's a bridge port can send per second. When
exceeded, transmission of the next BPDU will be delayed. (Range: 1-10; Default: 6)
◆
Max Hop Count
– The maximum number of hops allowed in the MST region before a
BPDU is discarded. (Range: 6-40; Default: 20)
An MST region is treated as a single node by the STP and RSTP protocols. Therefore, the
message age for BPDUs inside an MST region is never changed. However, each spanning
tree instance within a region, and the common internal spanning tree (CIST) that connects
these instances use a hop count to specify the maximum number of bridges that will
propagate a BPDU. Each bridge decrements the hop count by one before passing on the
BPDU. When the hop count reaches zero, the message is dropped.
Advanced Settings
◆
Edge Port BPDU Filtering
– BPDU filtering allows you to avoid transmitting BPDUs on
configured edge ports that are connected to end nodes. By default, STA sends BPDUs to
all ports regardless of whether administrative edge is enabled on a port. BDPU filtering is
configured on a per-port basis. (Default: Disabled)
◆
Edge Port BPDU Guard
– This feature protects edge ports from receiving BPDUs. It
prevents loops by shutting down an edge port when a BPDU is received instead of putting
it into the spanning tree discarding state. In a valid configuration, configured edge ports
should not receive BPDUs. If an edge port receives a BPDU, an invalid configuration exists,
Содержание GEP-1070
Страница 80: ...80 authentication from any point within the network...
Страница 168: ...168...