LevelOne FGP-2472, Руководство пользователя

Страница: 108 / 267

102
It is 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 more possibly.
Configured Path Cost:
The range is 0 – 200,000,000. In the switch, if path cost is set to be 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, it may show the value that the administrator set up in
Configured Path Cost and Path Cost Status.
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:
Priority here means Port Priority. Port Priority and Port Number are
mixed 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.
Default is 128.
Admin Edge Port:
If user selects “Yes”, this port will be an edge port. An Edge Port is a port
connected to a device that knows nothing about STP or RSTP. Usually,
the connected device is an end station. Edge Ports will immediately
transit to forwarding state and skip the listening and learning state
because the edge ports cannot create bridging loops in the network. This
will expedite the convergence. When the link on the edge port toggles,
the STP topology keeps unchanged. Unlike the designate port or root
port though, an edge port will transit to a normal spanning-tree port
immediately if it receives a BPDU.
Default: No
Admin Point To Point:
We say a port is a point-to-point link, from RSTP’s view, if it is in full-
duplex mode but is shared link if it is in half-duplex mode. RSTP fast
convergence can only happen on point-to-point links and on edge ports.
This can expedite the convergence because this will have the port fast
transited to forwarding state.
There are three parameters, Auto, True and False, used to configure the
type of the point-to-point link. If configure this parameter to be Auto, it
means RSTP will use the duplex mode resulted from the auto-negotiation.
In today’s switched networks, most links are running in full-duplex mode.
For sure, the result may be half-duplex, in this case, the port will not fast