Specifications

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Cisco MWR 2941 Mobile Wireless Edge Router Release 3.5 Software Configuration Guide, Cisco IOS Release 15.1(3)MR
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Chapter 11 Configuring Optional Spanning-Tree Features
Configuring Optional Spanning-Tree Features
You can also use the spanning-tree bpdufilter enable interface configuration command to enable
BPDU filtering on any STP port without also enabling the Port Fast feature. This command prevents the
STP port from sending or receiving BPDUs.
Caution Enabling BPDU filtering on an STP port is the same as disabling spanning tree on it and can result in
spanning-tree loops.
You can enable the BPDU filtering feature if your router is running PVST+ or MSTP.
Beginning in privileged EXEC mode, follow these steps to globally enable the BPDU filtering feature.
This procedure is optional.
To disable BPDU filtering, use the no spanning-tree portfast bpdufilter default global configuration
command.
You can override the setting of the no spanning-tree portfast bpdufilter default global configuration
command by using the spanning-tree bpdufilter enable interface configuration command on an STP
port.
Enabling Root Guard
Root guard enabled on an STP port applies to all the VLANs to which the port belongs.
Note You cannot enable both root guard and loop guard at the same time.
You can enable this feature if your router is running PVST+ or MSTP.
Beginning in privileged EXEC mode, follow these steps to enable root guard on an interface. This
procedure is optional.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
spanning-tree portfast bpdufilter default Globally enable BPDU filtering. (By default, BPDU filtering is
disabled.)
Note Globally enabling BPDU filtering enables it only on STP
ports; the command has no effect on UNIs or ENIs on
which STP is not enabled.
Step 3
interface interface-id Specify the interface connected to an end station, and enter
interface configuration mode.
Step 4
spanning-tree portfast Enable the Port Fast feature.
Step 5
end Return to privileged EXEC mode.
Step 6
show running-config Verify your entries.
Step 7
copy running-config startup-config (Optional) Save your entries in the configuration file.