Waters Network Systems
2800M/MR User’s Manual
Page 73
5.15.3
STP Port Configuration
Function name:
STP Port Setting
Function description:
In the STP Port Setting, one item selection and five
parameters are available for setup. You can
disable and enable each port. You can set
Path Cost
and
Priority
for each port and set
Admin
Edge Port
and
Admin Point To Point
.
Parameter description:
Port Status:
Displays the current state of a port for viewing only. According to the 802.1w specification,
there are three possible states.
DISCARDING state indicates that this port can neither forward packets nor contribute
learning knowledge.
LEARNING state indicates this port can now contribute its learning knowledge but cannot
forward packets.
FORWARDING state indicates this port can both contribute its learning knowledge and
forward packets normally.
Note
: Three other states (Disable state, BLOCKING state and LISTENING state) defined in the
802.1d specification are now represented as DISCARDING state.
Path Cost Status:
The contribution value of the path through this port to Root Bridge. STP algorithm determines a
best path to Root Bridge by calculating the sum of path cost contributed by all ports on this path.
A port with a smaller path cost value would become the Root Port.
Configured Path Cost:
The range is 0 – 200,000,000. If the path cost is set to zero, the STP will get the recommended
value resulted from auto-negotiation of the link accordingly and display this value in the field of
Path Cost Status. Otherwise, the value set by the administrator set up will be displayed.
802.1w RSTP recommended value: (Valid range: 1 – 200,000,000)
10 Mbps:
2,000,000
100 Mbps:
200,000
1 Gbps:
20,000
Default:
0
Priority:
Port Priority and Port Number are combined to form the Port ID. Port IDs are often compared in
order to determine which port of a bridge would become the Root Port. The range is 0 – 240.