Configuring the ECN330-switch
2451553-KDU 137 365 Uen D 2006-06-16
Figure 97 STA Port Roles
• 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. See the preceding item.
• Priority – Defines the priority used for this port in the Spanning Tree
Algorithm. If the path cost for all ports on an ECN330-switch is the
same, the port with the highest priority (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.
Alternate port receives more
useful BPDUs from another
bridge and is therefore not
selected as the designated
port.
x
R: Root Port
A: Alternate Port
D: Designated Port
B: Backup Port
RR
ADB
Backup port receives more
useful BPDUs from the same
bridge and is therefore not
selected as the designated
port.
x
RR
ADB