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Rapid Spanning Tree Protocol (RSTP)
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Multiple Spanning Tree Protocol (MSTP)
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Per-VLAN Spanning Tree Plus (PVST+)
•
You cannot enable root guard and loop guard at the same time on an STP port. For example, if you configure loop guard on a port
on which root guard is already configured, the following error message is displayed:
% Error: RootGuard is
configured. Cannot configure LoopGuard
.
•
Enabling Portfast BPDU guard and loop guard at the same time on a port results in a port that remains in a blocking state and
prevents traffic from flowing through it. For example, when Portfast BPDU guard and loop guard are both configured:
– If a BPDU is received from a remote device, BPDU guard places the port in an Err-Disabled Blocking state and no traffic is
forwarded on the port.
– If no BPDU is received from a remote device, loop guard places the port in a Loop-Inconsistent Blocking state and no traffic
is forwarded on the port.
•
When used in a PVST+ network, STP loop guard is performed per-port or per-port channel at a VLAN level. If no BPDUs are
received on a VLAN interface, the port or port-channel transitions to a Loop-Inconsistent (Blocking) state only for this VLAN.
To enable a loop guard on an STP-enabled port or port-channel interface, use the following command.
•
Enable loop guard on a port or port-channel interface.
INTERFACE mode or INTERFACE PORT-CHANNEL mode
spanning-tree {0 | mstp | rstp | pvst} loopguard
–
0
: enables loop guard on an STP-enabled port assigned to instance 0.
–
mstp
: enables loop guard on an MSTP-enabled port.
–
rstp
: enables loop guard on an RSTP-enabled port.
–
pvst
: enables loop guard on a PVST-enabled port.
To disable STP loop guard on a port or port-channel interface, use the
no spanning-tree 0 loopguard
command in an
INTERFACE configuration mode.
To verify the STP loop guard configuration on a port or port-channel interface, use the
show spanning-tree 0 guard
[interface
interface
]
command in a global configuration mode.
Displaying STP Guard Configuration
To display the STP guard configuration, use the following command.
The following example shows an STP network (instance 0) in which:
•
Root guard is enabled on a port that is in a root-inconsistent state.
•
Loop guard is enabled on a port that is in a listening state.
•
BPDU guard is enabled on a port that is shut down (Error Disabled state) after receiving a BPDU.
•
Verify the STP guard configured on port or port-channel interfaces.
show spanning-tree 0 guard [interface
interface
]
Example of Viewing STP Guard Configuration
Dell#show spanning-tree 0 guard
Interface
Name Instance Sts Guard type
--------- -------- --------- ----------
Te 1/1 0 INCON(Root) Rootguard
Te 1/2 0 LIS Loopguard
Te 1/3 0 EDS (Shut) Bpduguard
856
Spanning Tree Protocol (STP)
Содержание S4048-ON
Страница 1: ...Dell Configuration Guide for the S4048 ON System 9 9 0 0 ...
Страница 146: ...Figure 14 BFD Three Way Handshake State Changes 146 Bidirectional Forwarding Detection BFD ...
Страница 477: ...Figure 68 Inspecting Configuration of LAG 10 on ALPHA Link Aggregation Control Protocol LACP 477 ...
Страница 480: ...Figure 70 Inspecting a LAG Port on BRAVO Using the show interface Command 480 Link Aggregation Control Protocol LACP ...
Страница 481: ...Figure 71 Inspecting LAG 10 Using the show interfaces port channel Command Link Aggregation Control Protocol LACP 481 ...
Страница 522: ...Figure 87 Configuring Interfaces for MSDP 522 Multicast Source Discovery Protocol MSDP ...
Страница 523: ...Figure 88 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 523 ...
Страница 524: ...Figure 89 Configuring PIM in Multiple Routing Domains 524 Multicast Source Discovery Protocol MSDP ...
Страница 528: ...Figure 91 MSDP Default Peer Scenario 1 528 Multicast Source Discovery Protocol MSDP ...
Страница 529: ...Figure 92 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 529 ...
Страница 530: ...Figure 93 MSDP Default Peer Scenario 3 530 Multicast Source Discovery Protocol MSDP ...
Страница 633: ...Policy based Routing PBR 633 ...
Страница 777: ...Figure 119 Single and Double Tag TPID Match Service Provider Bridging 777 ...
Страница 778: ...Figure 120 Single and Double Tag First byte TPID Match 778 Service Provider Bridging ...