3com 8807 사용자 가이드
Configuring MSTP
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upstream port, some instances of the upstream port will be congested for a
long time.
long time.
By default, only the protection from TC-BPDU packet attack is enabled on the
switch. BPDU protection, Root protection and loop protection are disabled.
switch. BPDU protection, Root protection and loop protection are disabled.
After configured with BPDU protection, the switch will disable the edge port
through MSTP which receives a BPDU, and notify the network manager at same
time. These ports can be resumed by the network manager only.
through MSTP which receives a BPDU, and notify the network manager at same
time. These ports can be resumed by the network manager only.
The port configured with Root protection only plays a role of designated port on
every instance. Whenever such port receives a higher-priority BPDU, that is, it is
about to turn into non-designated port, it will be set to listening state and not
forward packets any more (as if the link to the port is disconnected). If the port has
not received any higher-priority BPDU for a certain period of time thereafter, it will
resume the normal state.
every instance. Whenever such port receives a higher-priority BPDU, that is, it is
about to turn into non-designated port, it will be set to listening state and not
forward packets any more (as if the link to the port is disconnected). If the port has
not received any higher-priority BPDU for a certain period of time thereafter, it will
resume the normal state.
For one port, only one configuration can be effective among loop protection, Root
protection and Edge port configuration at the same moment.
protection and Edge port configuration at the same moment.
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The port configured with loop protection can only turn into discarding state on
every instance. That such a port receives no configuration message for a long time
indicates that it is about to change its state and role. Only the port role changes
but the port discarding state remains unchanged, and no packets are forwarded.
In this way, if the peer end cannot send BPDU packets due to error operation, and
the port enters forwarding state directly for not receiving configuration message
for a long time, no loop will be generated by enabling the loop protection.
every instance. That such a port receives no configuration message for a long time
indicates that it is about to change its state and role. Only the port role changes
but the port discarding state remains unchanged, and no packets are forwarded.
In this way, if the peer end cannot send BPDU packets due to error operation, and
the port enters forwarding state directly for not receiving configuration message
for a long time, no loop will be generated by enabling the loop protection.
Enabling/Disabling
MSTP on the Device
You can use the following command to enable MSTP on the device.
Perform the following configuration in system view.
Only if MSTP has been enabled on the device will other MSTP configurations take
effect. If MSTP is disabled on the device, MSTP cannot be enabled on a port.
effect. If MSTP is disabled on the device, MSTP cannot be enabled on a port.
By default, MSTP is disabled.
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CAUTION: The MSTP function and the loop detection function are mutually
exclusive. Before enabling the MSTP function, you must judge whether the system
is detecting loops. If yes, you cannot enable the MSTP function.
exclusive. Before enabling the MSTP function, you must judge whether the system
is detecting loops. If yes, you cannot enable the MSTP function.
Enabling/Disabling
MSTP on a Port
You can use the following command to enable/disable MSTP on a port. You may
disable MSTP on some Ethernet ports of a switch to spare them from spanning
tree calculation. This is a measure to flexibly control MSTP operation and save the
CPU resources of the switch.
disable MSTP on some Ethernet ports of a switch to spare them from spanning
tree calculation. This is a measure to flexibly control MSTP operation and save the
CPU resources of the switch.
Table 132 Enable/Disable MSTP on a device
Operation
Command
Enable MSTP on a device
stp enable
Disable MSTP on a device
stp disable
Restore the disable state of MSTP, as
defaulted
defaulted
undo stp