Dell PowerConnect 2816 - Page 120

120 Update with your book title
• Port State — The current port STP state. If enabled, the port state determines what forwarding action
is taken on traffic. Possible port states are:
–
Disabled — The port link is currently down.
–
Blocking — The port is currently blocked and cannot be used to forward traffic or learn MAC
addresses. Blocking is displayed when Classic STP is enabled.
–
Listening — The port is currently in the listening mode. The port cannot forward traffic nor can it
learn MAC addresses.
–
Learning — The port is currently in the learning mode. The port cannot forward traffic however it
can learn new MAC addresses.
–
Forwarding — The port is currently in the forwarding mode. The port can forward traffic and learn
new MAC addresses.
•
Role — Displays the port role assigned by the STP algorithm to provide to STP paths. The possible
field values are:
–
Root — Provides the lowest cost path to forward packets to the root switch.
–
Designated — Indicates the port or LAG through which the designated switch is attached to the
LAN.
–
Alternate — Provides an alternate path to the root switch from the root interface.
–
Backup — Provides a backup path to the designated port path toward the Spanning Tree leaves.
Backup ports occur only when two ports are connected in a loop by a point-to-point link, or when a
LAN has two or more connections connected to a shared segment.
–
Disabled — The port is not participating in the Spanning Tree.
•
Speed — Speed at which the port is operating.
•
Path Cost (1-200000000) — The port contribution to the root path cost. The path cost is adjusted to
a higher or lower value, and is used to forward traffic when a path being rerouted.
•
Default Path Cost — The default path cost of the port is automatically set by the port speed and the
default path cost method.
The default values for long path costs are:
– Ethernet - 2000000
–
Fast Ethernet - 200000
–
Gigabit Ethernet - 20000
The default values for short path costs (short path costs are the default) are:
– Ethernet - 100
–
Fast Ethernet - 19
–
Gigabit Ethernet - 4