STRIDE SE-MC2U-SC, Руководство пользователя

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This option may be set per port per MSTI.
If the switch has more than one port that provides a path to the root bridge and they have the
same root path cost, the selection of which port to use is based on the port priority. The port
with the best (numerically lowest) priority will be used. If the port priority is the same, the
switch will use the lowest numbered port. The port priority can range from 0 to 240 seconds
(128 second default).
Path Cost (1 to 200,000,000; Default = 20,000 for 10 / 100 / 1000 ports and 200,000 for
10 / 100 ports): As with any network, there is an associated cost to go from a source location
to a destination location. For RSTP, the root path cost is calculated based on the bandwidth
available for that particular connection to the root bridge. The port with the lowest cost for
delivering messages to the root is used to pass traffic toward the root.
The path cost can be assigned automatically based on the port speed, using the IEEE standard
values of 200,000 for 100Mbps links and 2,000,000 for 10Mbps links, or the value can be
specified in the range 1 to 200,000,000.
The default value depends on the capabilities of the port: 200,000 for 100 Mbps and 20,000
for 1000 Mbps ports.
This option can be set per port per MSTI.
See RSTP Examples for an illustration of how the path cost can be utilized to establish the
primary and backup connections.
Type (Default = Auto): A port that connects to other switches in the network may be part of
a loop. To ensure such loops do not occur, the switch will not put a port in the Forwarding
state until enough time has passed for the spanning tree to stabilize (twice the forwarding
delay, 30 seconds by default). However, if a port connects directly to a single device at the
edge of the network, it may safely be put in Forwarding state almost immediately. The port
Type controls the switch’s assumptions about what is connected to the port.
• Auto: The port will initially be assumed to be an Edge port and go to Forwarding quickly. It will
automatically adjust to being a Network port if BPDUs are received and revert to being an Edge
port any time no BPDUs are received for 3 seconds.
• Network:
The port will always wait a safe time before going to the Forwarding state.
• Edge: The port will initially be assumed to be a direct connection to a single device but will change
to being a Network port if any BPDUs are received. Thereafter, it will always wait a safe time before
going to Forwarding whenever a link is reestablished on the port.
This option can be set per port per MSTI.
Point-to-Point (Default = Auto): A port is part of a point-to-point network segment when
there can be no more than one other network port connected to it. RSTP can decide whether
it is safe to forward network traffic very quickly on point-to-point links to other managed
switches, otherwise the port must wait many seconds (30 seconds by default, twice the
forward delay) before forwarding network traffic. When set to Auto, full-duplex links are
assumed to be point-to-point; half-duplex ports are not. This setting can be forced true or
false if the automatic determination would be wrong.
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Chapter 4 - Managed Switch Software Setup
Stride Industrial Ethernet Switches User Manual 2nd Ed. Rev. A