Spanning Tree Protocol |
1057
To enable PortFast on an interface:
Verify that PortFast is enabled on a port using the
show spanning-tree
command from the EXEC privilege
mode or the
show config
command from INTERFACE mode; Dell Force10 recommends using the
show
config
command, as shown in
Figure 52-7
.
Figure 52-7. PortFast Enabled on Interface
Preventing Network Disruptions with BPDU Guard
The Portfast (and Edgeport, in the case of RSTP, PVST+, and MSTP) feature should be configured 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 BPDUs. If an edge port does receive a BPDU, it likely means
that it is connected to another part of the network, which can negatively effect the STP topology.
The BPDU Guard feature blocks an edge port upon receiving a BPDU to prevent network disruptions, and
FTOS displays
Message 1
.
Enable BPDU Guard using the option
bpduguard
when enabling PortFast or EdgePort. Configure the
bpduguard shutdown-on-violation
option to cause the interface hardware to shut down when it receives a
BPDU. Otherwise with only the option enabled, 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.
Task
Command Syntax
Command Mode
Enable PortFast on an interface.
spanning-tree
stp-id
portfast
[
bpduguard
[
shutdown-on-violation
]]
INTERFACE
Caution:
Do not enable Portfast BPDU guard and loop guard at the same time on a port. Enabling both features
may result 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.
FTOS#(conf-if-gi-1/1)#show conf
!
interface GigabitEthernet 1/1
no ip address
switchport
spanning-tree 0 portfast
no shutdown
FTOS#(conf-if-gi-1/1)#
Indicates that the interface is in PortFast mode
Summary of Contents for Force10 E300
Page 1: ...FTOS Configuration Guide FTOS 8 4 2 7 E Series TeraScale C Series S Series S50 S25 ...
Page 32: ...32 w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 132: ...132 802 1X w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 310: ...310 Configuration Replace and Rollback w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 330: ...330 Dynamic Host Configuration Protocol w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 402: ...402 High Availability w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 462: ...462 Interfaces w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 482: ...482 IPv4 Addressing w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 506: ...506 IPv6 Addressing w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 582: ...582 Layer 2 w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 642: ...642 Multicast Source Discovery Protocol w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 662: ...662 Multiple Spanning Tree Protocol w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 690: ...690 Object Tracking w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 754: ...754 PIM Dense Mode w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 784: ...784 PIM Source Specific Mode w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 800: ...800 Power over Ethernet w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 876: ...876 Quality of Service w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 892: ...892 Routing Information Protocol w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1006: ...1006 Simple Network Management Protocol w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1018: ...1018 SONET SDH w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1048: ...1048 Broadcast Storm Control w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1096: ...1096 Uplink Failure Detection UFD w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1098: ...1098 Upgrade Procedures w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1196: ...1196 C Series Debugging and Diagnostics w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1252: ...1252 Standards Compliance w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1262: ...1262 Index w w w d e l l c o m s u p p o r t d e l l c o m ...