beautypg.com

Advanced / trunking – Xerox KS-801 User Manual

Page 53

background image

-53-

STP (Spanning Tree Protocol) Port Status

Port Number

The LAN port ID

Path Cost

The Spanning-Tree Protocol uses port path costs to
determine which port to select as a forwarding port.
You should assign lower numbers to ports attached
to faster media (such as full duplex), and higher
numbers to ports attached to slower media. The
possible range is 1 to 65535. The recommended path
cost is 1000 ¡Ò LAN speed in megabits per second.

Priority

The port (physical or logical) with the lowest priority
value has the highest priority and forwards the
spanning-tree frames. The possible priority range is 0
through 255 (decimal). The default is 128. If all ports
have the same priority value, the lowest port number
forwards the spanning-tree frames.

Port Status

Ports which are enabled can be in one of the follow-
ing states:

Listening : Switches send messages to one another
to establish the network topology and the optimal
paths to the different segments of the network. Other
data is not transmitted.

Blocking : The switch enters the Blocking State if a
path with higher priority is found to exist during the
Listening State. Normal data is not transmitted.

Learning : The switch enters the Learning State if no
path with a higher priority is found during the
Listening State. Learned entries are entered in the
Unicast Destination Forwarding Table. Normal data
is not transmitted.

Forwarding : The switch enters the Forwarding State
after having been in the Learning State for a pre-
defined time period. Normal data is transmitted.