Dell PowerConnect 54 Series, User Manual

Page: 285 / 416

Configuring Device Information
285
• LAG State — Current STP state of a LAG. If enabled, the LAG state determines what forwarding action
is taken on traffic. If the bridge discovers a malfunctioning LAG, the LAG is placed in the Broken state.
Possible LAG states are:
–
Disabled — The LAG link is currently down.
– Blocking — The LAG is blocked and cannot be used to forward traffic or learn MAC addresses.
– Listening — The LAG is in the listening mode and cannot forward traffic or learn MAC addresses.
– Learning — The LAG is in the learning mode and cannot forward traffic, but it can learn new MAC
addresses.
– Forwarding — The LAG is currently in the forwarding mode, and it can forward traffic and learn
new MAC addresses.
– Broken — The LAG is currently malfunctioning and cannot be used for forwarding traffic.
• 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.
• Path Cost (1-200000000) — Amount the LAG contributes 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. The path cost has a
value of 1 to 200000000. If the path cost method is short, the LAG cost default value is 4. If the path cost
method is long, the LAG cost default value is 20000.
• Default Path Cost — When selected, the LAG path cost returns to its default value.
• Priority — The priority value of the LAG. The priority value influences the LAG choice when a bridge
has two looped ports. The priority value is between 0-240, in increments of 16.
• Designated Bridge ID — The bridge priority and the MAC Address of the designated bridge.
• Designated Port ID — The port priority and interface number of the designated port.
• Designated Cost — The cost of the designated bridge.
• Forward Transitions — The number of times the LAG State has changed from the Blocking state to a
Forwarding state.