PVST+ Protect
The following figure illustrates how a Cisco device running MSTP puts the port in a blocking state.
The processes are summarized as follows:
- RUCKUS and Cisco MSTP work correctly together, without any PVST devices in the topology.
- A PVST device is connected. RUCKUS MSTP devices flood PVST frames across topology.
- MSTP between RUCKUS and Cisco no longer works correctly, because Cisco assumes legacy PVST device is connected.
To configure PVST+ Protect, complete the following steps in any order:
- In global configuration mode, enter the
errdisable recovery causecommand and specify pvstplus-protect as the cause. If you do not enable automatic recovery, blocked ports will remain blocked. - Optionally, in global configuration mode, enter the
errdisable recovery intervalcommand and specify a non-default recovery interval. (The default is 300 seconds.) - In interface configuration mode, enter the
pvstplus-protectcommand on an interface to be protected.
pvstplus-protect command cannot be issued concurrently with the
pvst-mode command. The following error message appears:
PVST mode not allowed on a PVST+ Protect mode
To change the recovery interval from the default, use the
errdisable recovery interval command.
device(config)# errdisable recovery interval 150
To confirm the error recovery status, use the
show errdisable recovery command.
device# show errdisable recovery ErrDisable Reason Timer Status ----------------------------------------------------------------------------- all reason Disabled bpduguard Disabled loopDetection Disabled invalid license Disabled packet-inerror Disabled loam-critical-event Disabled Reload the switch or stack to enable this port in 10G speed Disabled stack-port-resiliency Disabled broadcast traffic threshold exceeded Disabled multicast traffic threshold exceeded Disabled unknown unicast traffic threshold exceeded Disabled pvstplus-protect Enabled Timeout Value: 60 seconds Interface that will be enabled at the next timeout: Interface Errdisable reason Time left (sec) -------------- ----------------- --------------- Port 1/1/1 pvstplus-protect 31
To enable PVST+ Protect on a single port, use the
pvstplus-protect command.
device(config)# interface ethernet 1/1/1 device(config-if-1/1/1)# pvstplus-protect
To confirm the running configuration on a specified Ethernet interface, use the
show running-config interface ethernet command.
device# show running-config interface ethernet 1/1/1 interface ethernet 1/1/1 port-name ToCisco1 pvstplus-protect
To display the status of PVST+ Protect on the
Ethernet interface, including the number of dropped PVST+ BPDUs:, use the show
pvstplus-protect-ports command.
device# show pvstplus-protect-ports ethernet 1/1/1
Port PVST Drop Count
1/1/1 2
To enable PVST+ Protect on a range of ports in interface configuration mode, use
the
pvstplus-protect command.
device(config)# interface ethernet 1/1/1 to 1/1/4 device(config-mif-1/1/1-1/1/4)# pvstplus-protect
To confirm the configuration on a specified Ethernet interface, use the
show interface ethernet command.
device# show interface ethernet 1/1/1 GigabitEthernet1/1/1 is ERR-DISABLED (pvstplus-protect), line protocol is down Port down for 3 second(s) Hardware is GigabitEthernet, address is cc4e.2407.affe (bia cc4e.2407.affe) Configured speed auto, actual unknown, configured duplex fdx, actual unknown Configured mdi mode AUTO, actual unknown Tagged member of 7 L2 VLANs, untagged in VLAN 1, port state is DISABLED BPDU guard is Disabled, ROOT protect is Disabled, Designated protect is Disabl ed Link Error Dampening is Disabled STP configured to ON, priority is level0, mac-learning is enabled Flow Control is config enabled, oper disabled, negotiation disabled Mirror disabled, Monitor disabled Mac-notification is disabled Not member of any active trunks Not member of any configured trunks Port name is ToCisco1 Inter-Packet Gap (IPG) is 96 bit times MTU 1500 bytes 300 second input rate: 0 bits/sec, 0 packets/sec, 0.00% utilization 300 second output rate: 0 bits/sec, 0 packets/sec, 0.00% utilization 8027 packets input, 561171 bytes, 0 no buffer Received 0 broadcasts, 8022 multicasts, 5 unicasts 0 input errors, 0 CRC, 0 frame, 0 ignored 0 runts, 0 giants 2487 packets output, 420635 bytes, 0 underruns Transmitted 0 broadcasts, 2487 multicasts, 0 unicasts 0 output errors, 0 collisions Relay Agent Information option: Disabled Egress queues: Queue counters Queued packets Dropped Packets 0 0 0 1 0 0 2 0 0 3 0 0 4 0 0 5 0 0 6 0 0 7 0 0
To view the logging status, use the
show logging command.
device# show logging
Syslog logging: enabled ( 0 messages dropped, 0 flushes, 226 overruns)
Buffer logging: level ACDMEINW, 50 messages logged
level code: A=alert C=critical D=debugging M=emergency E=error
I=informational N=notification W=warning
Static Log Buffer:
Dec 31 18:00:40:I:System: Stack unit 1 POE PS 1, Internal Power supply with 68
000 mwatts capacity is up
Dynamic Log Buffer (50 lines):
Jan 4 13:49:49:I:System: Interface ethernet 1/1/1, state down
Jan 4 13:49:49:I:MSTP: MST 0 Port 1/1/1 - DISCARDING
Jan 4 13:49:49:I:MSTP: MST 2 Port 1/1/1 - DISCARDING
Jan 4 13:49:49:I:MSTP: MST 1 Port 1/1/1 - DISCARDING
Jan 4 13:49:49:I:PVST: Received PVST+ BPDU on PVST+ Protect enabled Port 1/1/1
, Vlan 100. Error Disabling
<---output omitted--->
To clear the PVST+ Protect statistics for one or more specified Ethernet ports:
device# clear pvstplus-protect-statistics ethernet 1/1/1