Cabletron Systems 9H42X-XX Manual Do Utilizador
Bridge Spanning Tree
5-15
Bridging
expires, the port transmits its Configuration BPDU to send configuration
information to the Root. The Hold Time is a fixed value, as specified by the IEEE
802.1d specification.
information to the Root. The Hold Time is a fixed value, as specified by the IEEE
802.1d specification.
Port-specific Parameters
The following fields are applicable to each bridge port interface present on the
selected 9H42x-xx module:
selected 9H42x-xx module:
Priority
If two or more ports on the same bridge are connected to the same LAN segment,
they will receive the same Root ID/Root Cost/Bridge ID information in
Configuration BPDUs received at each port. In this case, the BPDU’s Port ID
information — the transmitting port’s identifier and its manageable Priority
component — is used to determine which is the Designated Port for that segment.
they will receive the same Root ID/Root Cost/Bridge ID information in
Configuration BPDUs received at each port. In this case, the BPDU’s Port ID
information — the transmitting port’s identifier and its manageable Priority
component — is used to determine which is the Designated Port for that segment.
A lower assigned value gives the port a higher Priority when BPDUs are
compared. The allowable range is 0-FF hexadecimal (0-255 decimal); the default is
80 hexadecimal.
compared. The allowable range is 0-FF hexadecimal (0-255 decimal); the default is
80 hexadecimal.
Path Cost
Displays the cost that this port will contribute to the calculation of the overall
Root path cost in a Configuration BPDU transmitted by this bridge port. You can
lower a port’s Path Cost to make the port more competitive in the selection of the
Designated Port – for example, you may want to assign a lower path cost to a port
on a higher performance bridge. The allowable range is 1 to 65535.
Root path cost in a Configuration BPDU transmitted by this bridge port. You can
lower a port’s Path Cost to make the port more competitive in the selection of the
Designated Port – for example, you may want to assign a lower path cost to a port
on a higher performance bridge. The allowable range is 1 to 65535.
Designated Cost
Displays the cost of the path to the Root Bridge of the Designated Port on the
LAN to which this port is attached. This cost is added to the Path Cost to test the
value of the Root Path Cost parameter received in Configuration BPDUs.
LAN to which this port is attached. This cost is added to the Path Cost to test the
value of the Root Path Cost parameter received in Configuration BPDUs.
Designated Root
Displays the unique bridge identifier of the bridge that is assumed to be the Root
Bridge.
Bridge.
Designated Bridge
Displays the network address portion of the Bridge ID (MAC address/priority
component) for the bridge that is believed to be the Designated Bridge for the
LAN associated with this port.
component) for the bridge that is believed to be the Designated Bridge for the
LAN associated with this port.
The Designated Bridge ID, along with the Designated Port and Port Identifier
parameters for the port, is used to determine whether this port should be the
Designated Port for the LAN to which it is attached. The Designated Bridge ID is
also used to test the value of the Bridge Identifier parameter in received BPDUs.
parameters for the port, is used to determine whether this port should be the
Designated Port for the LAN to which it is attached. The Designated Bridge ID is
also used to test the value of the Bridge Identifier parameter in received BPDUs.