Dell S4048T, Руководство по настройке

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Prevent Network Disruptions with BPDU Guard
Configure the Portfast (and Edgeport, in the case of RSTP, PVST+, and MSTP) feature on ports that connect to
end stations. End stations do not generate BPDUs, so ports configured with Portfast/ Edgport (edgeports) do
not expect to receive BDPUs.
If an edgeport does receive a BPDU, it likely means that it is connected to another part of the network, which
can negatively affect the STP topology. The BPDU Guard feature blocks an edgeport after receiving a BPDU
to prevent network disruptions, and Dell Networking OS displays the following message.
3w3d0h: %RPM0-P:RP2 %SPANMGR-5-BPDU_GUARD_RX_ERROR: Received Spanning Tree BPDU on
BPDU guard port. Disable TenGigabitEthernet 3/4.
Enable BPDU Guard using the
bpduguard
option when enabling PortFast or EdgePort. The
bpduguard
shutdown-on-violation
option causes the interface hardware to be shut down when it receives a BPDU.
Otherwise, although the interface is placed in an Error Disabled state when receiving the BPDU, the physical
interface remains up and spanning-tree will only drop packets after a BPDU violation.
The following example shows a scenario in which an edgeport might unintentionally receive a BPDU. The
port on the Dell Networking system is configured with Portfast. If the switch is connected to the hub, the
BPDUs that the switch generates might trigger an undesirable topology change. If you enable BPDU Guard,
when the edge port receives the BPDU, the BPDU is dropped, the port is blocked, and a console message is
generated.
NOTE: Unless you enable the
shutdown-on-violation
option, spanning-tree only drops packets after
a BPDU violation; the physical interface remains up.
Dell Networking OS Behavior : Regarding
bpduguard shutdown-on-violation
behavior:
• If the interface to be shut down is a port channel, all the member ports are disabled in the hardware.
• When you add a physical port to a port channel already in the Error Disable state, the new member port
is also disabled in the hardware.
• When you remove a physical port from a port channel in the Error Disable state, the Error Disabled state
is cleared on this physical port (the physical port is enabled in the hardware).
• You can clear the Error Disabled state with any of the following methods:
• Perform a
shutdown
command on the interface.
• Disable the
shutdown-on-violation
command on the interface (the
no spanning-tree
stp-id portfast [bpduguard | [shutdown-on-violation]]
command).
• Disable spanning tree on the interface (the
no spanning-tree
command in INTERFACE mode).
Spanning Tree Protocol (STP) 1053