User`s manual

User’s Manual 43
Forward Transitions – The number of times this port has transitioned from the Learning state to the
Forwarding state.
Designated Cost – The cost for a packet to travel from this port to the root in the current Spanning Tree
configuration. The slower the media, the higher the cost.
Designated Bridge – The bridge priority and MAC address of the device through which this port must
communicate to reach the root of the Spanning Tree.
Designated Port – The port priority and number of the port on the designated bridging device through which
this switch must communicate with the root of the Spanning Tree.
Oper Link Type – The operational point-to-point status of the LAN segment attached to this interface. This
parameter is determined by manual configuration or by auto-detection, as described for Admin Link Type in
STA Port Configuration in section 3.2 Configuring Interface Settings.
Oper Edge Port – This parameter is initialized to the setting for Admin Edge Port in STA Port Configuration
in section 3.2 Configuring Interface Settings (for example, true or false), but will be set to false if a BPDU
is received, indicating that another bridge is attached to this port.
Port Role – Roles are assigned according to whether the port is part of the active topology connecting the
bridge to the root bridge (for example, root port), connecting a LAN through the bridge to the root bridge (for
example, designated port), or is the MSTI regional root (for example, master port). The are also assigned as
an alternate or backup port that may provide connectivity if other bridges, bridge ports, or LANs fail or are
removed. The role is set to disabled (For example, disabled port) if a port has no role within the spanning
tree.
Trunk Member – Indicates if a port is a member of a trunk. (STA Port Information only)
These additional parameters are only displayed for the CLI:
Admin status – Shows if this interface is enabled.
External path cost – The path cost for the IST. This parameter is used by the STA to determine the best
path between devices. Therefore, lower values should be assigned to ports attached to faster media, and
higher values assigned to ports with slower media. (Path cost takes precedence over port priority.)
Internal path cost – The path cost for the MST. Refer to the proceeding item “External Path Cost” for more
information.
Priority – Defines the priority used for this port in the Spanning Tree Algorithm. If the path cost for all ports
on a switch is the same, the port with the highest priority (For example, lowest value) will be configured as
an active link in the Spanning Tree. This makes a port with higher priority less likely to be blocked if the
Spanning Tree Algorithm is detecting network loops. Where more than one port is assigned the highest
priority, the port with the lowest numeric identifier will be enabled.
Designated root – The priority and MAC address of the device in the Spanning Tree that this switch has
accepted as the root device.
Fast forwarding – This field provides the same information as Admin Edge port, and is only included for
backward compatibility with earlier products.
Admin Edge Port – You can enable this option if an interface is attached to a LAN segment that is at the end
of a bridged LAN or to an end node. Since end nodes cannot cause forwarding loops, they can pass directly
through to the spanning tree forwarding state. Specifying Edge Ports provides quicker convergence for
devices such as workstations or servers, retains the current forwarding database to reduce the amount of
frame flooding required to rebuild address tables during reconfiguration events, does not cause the spanning