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Catalyst 4500 Series Switch Cisco IOS Command Reference, 12.2(25)SG
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Quick Links to Catalyst 4500 Series Switch Cisco IOS Commands
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Index
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Preface
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Command-Line Interface
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aaa accounting dot1x default start-stop group radius through instance
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interface port-channel through shape
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show access-group mode interface through show vtp
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snmp ifindex clear through vtp v2-mode
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Acronymns
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Acknowledgements for Open-Source Software
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Table Of Contents
snmp-server ifindex persist compress
spanning-tree etherchannel guard misconfig
spanning-tree extend system-id
spanning-tree loopguard default
spanning-tree mst configuration
spanning-tree mst forward-time
spanning-tree portfast (interface configuration mode)
spanning-tree portfast bpdufilter default
spanning-tree portfast bpduguard default
spanning-tree portfast default
storm-control broadcast include multicast
switchport private-vlan association trunk
switchport private-vlan host-association
switchport private-vlan mapping
switchport private-vlan trunk allowed vlan
switchport private-vlan trunk native vlan tag
udld (global configuration mode)
udld (interface configuration mode)
vlan internal allocation policy
vmps reconfirm (global configuration)
vmps reconfirm (privileged EXEC)
vtp (global configuration mode)
2.2snmp ifindex clear
To clear any previously configured snmp ifindex commands that were entered for a specific interface, use the snmp ifindex clear command.
snmp ifindex clear
Syntax Description
This command has no arguments or keywords.
Defaults
This command has no default settings.
Command Modes
Interface configuration mode
Command History
12.1(19)EW
Support for this command was introduced on the Catalyst 4500 series switches.
Usage Guidelines
Interface index persistence occurs when ifIndex values in the interface MIB (IF-MIB) persist across reboots and allow for consistent identification of specific interfaces using SNMP.
Use the snmp ifindex clear command on a specific interface when you want that interface to use the global configuration setting for ifIndex persistence. This command clears any ifIndex configuration commands previously entered for that specific interface.
Examples
This example shows how to enable ifIndex persistence for all interfaces:
Router(config)# snmp-server ifindex persistThis example shows how to disable IfIndex persistence for FastEthernet 1/1 only:
Router(config)# interface fastethernet 1/1Router(config-if)# no snmp ifindex persistRouter(config-if)# exitThis example shows how to clear the ifIndex configuration from the FastEthernet 1/1 configuration:
Router(config)# interface fastethernet 1/1Router(config-if)# snmp ifindex clearRouter(config-if)# exitAs a result of this sequence of commands, ifIndex persistence is enabled for all interfaces that are specified by the snmp-server ifindex persist global configuration command.
Related Commands
snmp ifindex persist
snmp-server ifindex persistsnmp ifindex persist
To enable ifIndex values in the Interfaces MIB (IF-MIB) that persist across reboots (ifIndex persistence) on a specific interface, use the snmp ifindex persist command. To disable ifIndex persistence only on a specific interface, use the no form of this command.
snmp ifindex persist
no snmp ifindex persist
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled.
Command Modes
Interface configuration mode
Command History
12.1(19)EW
Support for this command was introduced on the Catalyst 4500 series switches.
Usage Guidelines
Interface index persistence occurs when ifIndex values in the IF-MIB persist across reboots and allow for consistent identification of specific interfaces using SNMP.
The snmp ifindex persist interface configuration command enables and disables ifIndex persistence for individual entries (that correspond to individual interfaces) in the ifIndex table of the IF-MIB.
The snmp-server ifindex persist global configuration command enables and disables ifIndex persistence for all interfaces on the routing device. This action applies only to interfaces that have ifDescr and ifIndex entries in the ifIndex table of the IF-MIB.
Examples
This example shows how to enable ifIndex persistence for interface FastEthernet 1/1 only:
Router(config)# interface fastethernet 1/1Router(config-if)# snmp ifindex persistRouter(config-if)# exitThis example shows how to enable ifIndex persistence for all interfaces, and then disable ifIndex persistence for interface FastEthernet 1/1 only:
Router(config)# snmp-server ifindex persistRouter(config)# interface fastethernet 1/1Router(config-if)# no snmp ifindex persistRouter(config-if)# exitRelated Commands
snmp ifindex clear
snmp-server ifindex persistsnmp-server enable traps
To enable SNMP notifications (traps or informs), use the snmp-server enable traps command. To disable all SNMP notifications, use the no form of this command.
snmp-server enable traps [flash [insertion | removal] | fru-ctrl |
port-security [trap-rate trap-rate] | removal | stpx | vlancreate | vlandelete | vtp]no snmp-server enable traps flash [insertion | removal] | fru-ctrl | port-security [trap-rate trap-rate] | removal | stpx | vlancreate | vlandelete | vtp]
Syntax Description
Defaults
SNMP notifications are disabled.
Command Modes
Global configuration
Command History
12.1(13)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
If you enter this command without an option, all notification types controlled by this command are enabled.
SNMP notifications can be sent as traps or inform requests. This command enables both traps and inform requests for the specified notification types. To specify whether the notifications should be sent as traps or informs, use the snmp-server host [traps | informs] command.
The snmp-server enable traps command is used in conjunction with the snmp-server host command. Use the snmp-server host command to specify which host or hosts receive SNMP notifications. To send notifications, you must configure at least one snmp-server host command.
This list of the MIBs is used for the traps:
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flash—Controls SNMP FLASH traps from the CISCO-FLASH-MIB.
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–
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•
•
•
•
•
Examples
This example shows how to send all traps to the host is specified by the name myhost.cisco.com using the community string defined as public:
Switch(config)# snmp-server enable trapsSwitch(config)# snmp-server host myhost.cisco.com publicSwitch(config)#Related Commands
Refer to Cisco IOS documentation for additional snmp-server enable traps commands.
snmp-server ifindex persist
To globally enable ifIndex values that will remain constant across reboots for use by SNMP, use the snmp-server ifindex persist command. To globally disable inIndex persistence, use the no form of this command.
snmp-server ifindex persist
no snmp-server ifindex persist
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled.
Command Modes
Global configuration mode
Command History
12.1(19)EW
Support for this command was introduced on the Catalyst 4500 series switches.
Usage Guidelines
Interface index persistence occurs when ifIndex values in the IF-MIB persist across reboots and allow for consistent identification of specific interfaces using SNMP.
The snmp-server ifindex persist global configuration command does not override the interface-specific configuration. To override the interface-specific configuration of ifIndex persistence, enter the no snmp ifindex persist and snmp ifindex clear interface configuration commands.
Entering the no snmp-server ifindex persist global configuration command enables and disables ifIndex persistence for all interfaces on the routing device using ifDescr and ifIndex entries in the ifIndex table of the IF-MIB.
Examples
This example shows how to enable ifIndex persistence for all interfaces:
Router(config)# snmp-server ifindex persistRelated Commands
snmp ifindex clear
snmp ifindex persistsnmp-server ifindex persist compress
To configure the format of the ifIndex table in a compressed format, use the snmp-server ifindex persist compress command. To place the table in a decompressed format, use the no form of this command.
snmp-server ifindex persist compress
no snmp-server ifindex persist compress
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Global configuration mode.
Command History
12.2(20)EWA
Support for this command was introduced on the Catalyst 4500 series switches.
Usage Guidelines
This command is hidden on Supervisor Engine V and later supervisor engines because the ifIndex table is always in a compressed format on those supervisor engines.
At bootup, if the nvram:ifIndex-table.gz file (the ifIndex table ina compressed format) is present on a Supervisor Engine II+, Supervisor Engine III, or Supervisor Engine IV, the snmp-server ifindex persist compress command is automatically run even if the startup-config file does not have this configuration.
Examples
This example shows how to enable compression of the ifIndex table:
Router(config)# snmp-server ifindex persist compressThis example shows how to disable compression of the ifIndex table:
Router(config)# no snmp-server ifindex persist compressRelated Commands
snmp ifindex clear
snmp ifindex persist
snmp-server ifindex persistspanning-tree backbonefast
To enable BackboneFast on a spanning-tree VLAN, use the spanning-tree backbonefast command. To disable BackboneFast, use the no form of this command.
spanning-tree backbonefast
no spanning-tree backbonefast
Syntax Description
This command has no arguments or keywords.
Defaults
BackboneFast is disabled.
Command Modes
Global configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
BackboneFast should be enabled on all Catalyst 4006 family switches to allow the detection of indirect link failures. Enabling BackboneFast starts the spanning-tree reconfiguration more quickly.
Examples
This example shows how to enable BackboneFast on all VLANs:
Switch(config)# spanning-tree backbonefastSwitch(config)#Related Commands
spanning-tree cost
spanning-tree port-priority
spanning-tree portfast default
spanning-tree portfast (interface configuration mode)
spanning-tree uplinkfast
spanning-tree vlan
show spanning-treespanning-tree bpdufilter
To enable BPDU filtering on an interface, use the spanning-tree bpdufilter command. To return to the default settings, use the no form of this command.
spanning-tree bpdufilter {enable | disable}
no spanning-tree bpdufilter
Syntax Description
Defaults
Disabled
Command Modes
Interface configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
Caution
When configuring Layer 2 protocol tunneling on all the service provider edge switches, you must enable spanning-tree BPDU filtering on the 802.1Q tunnel ports by entering the spanning-tree bpdufilter enable command.
BPDU filtering allows you to prevent a port from sending and receiving BPDUs. The configuration is applicable to the whole interface, whether it is trunking or not. This command has three states:
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•
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Examples
This example shows how to enable the BPDU filter feature on this interface:
Switch(config-if)# spanning-tree bpdufilter enableSwitch(config-if)#Related Commands
show spanning-tree
spanning-tree portfast bpdufilter defaultspanning-tree bpduguard
To enable BPDU guard on an interface, use the spanning-tree bpduguard command. To return to the default settings, use the no form of this command.
spanning-tree bpduguard {enable | disable}
no spanning-tree bpduguard
Syntax Description
Defaults
BPDU guard is disabled.
Command Modes
Interface configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
BPDU guard is a feature that prevents a port from receiving BPDUs. This feature is typically used in a service provider environment where the administrator wants to prevent an access port from participating in the spanning tree. If the port still receives a BPDU, it is put in the ErrDisable state as a protective measure. This command has three states:
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•
•
Examples
This example shows how to enable BPDU guard on this interface:
Switch(config-if)# spanning-tree bpduguard enableSwitch(config-if)#Related Commands
show spanning-tree
spanning-tree portfast bpduguard defaultspanning-tree cost
To calculate the path cost of STP on an interface, use the spanning-tree cost command. To revert to the default, use the no form of this command.
spanning-tree cost cost
no spanning-tree cost cost
Syntax Description
Defaults
The default settings are as follows:
•
•
Command Modes
Interface configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
When you configure the cost, the higher values indicate higher costs. The range applies regardless of the protocol type that is specified. The path cost is calculated, based on the interface bandwidth.
Examples
This example shows how to access an interface and set a path cost value of 250 for the spanning-tree VLAN that is associated with that interface:
Switch(config)# interface fastethernet 2/1Switch(config-if)# spanning-tree cost 250Switch(config-if)#Related Commands
spanning-tree port-priority
spanning-tree portfast default
spanning-tree portfast (interface configuration mode)
spanning-tree uplinkfast
spanning-tree vlan
show spanning-treespanning-tree etherchannel guard misconfig
To display an error message when a loop due to a channel misconfiguration is detected, use the spanning-tree etherchannel guard misconfig command. To disable the feature, use the no form of this command.
spanning-tree etherchannel guard misconfig
no spanning-tree etherchannel guard misconfig
Syntax Description
This command has no arguments or keywords.
Defaults
Spanning-tree EtherChannel guard is enabled.
Command Modes
Global configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
When an EtherChannel guard misconfiguration is detected, this message is displayed:
%SPANTREE-2-CHNL_MISCFG:Detected loop due to etherchannel misconfig of interface Port-Channel1To determine which local ports are involved in the misconfiguration, enter the show interfaces status err-disabled command. To check the EtherChannel configuration on the remote device, enter the show etherchannel summary command on the remote device.
After you correct the configuration, enter the shutdown and the no shutdown commands on the associated port-channel interface.
Examples
This example shows how to enable the EtherChannel guard misconfiguration feature:
Switch(config)# spanning-tree etherchannel guard misconfigSwitch(config)#Related Commands
show etherchannel
show interfaces status
shutdown (refer to Cisco IOS documentation)spanning-tree extend system-id
To enable the extended system ID feature on a chassis that supports 1024 MAC addresses, use the spanning-tree extend system-id command. To disable the feature, use the no form of this command.
spanning-tree extend system-id
no spanning-tree extend system-id
Syntax Description
This command has no arguments or keywords.
Defaults
Enabled on systems that do not provide 1024 MAC addresses.
Command Modes
Global configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
Releases 12.1(13)E and later support chassis with 64 or 1024 MAC addresses. For chassis with 64 MAC addresses, STP uses the extended system ID plus a MAC address to make the bridge ID unique for each VLAN.
You cannot disable the extended system ID on chassis that support 64 MAC addresses.
Enabling or disabling the extended system ID updates the bridge IDs of all active STP instances, which might change the spanning-tree topology.
Examples
This example shows how to enable the extended system ID:
Switch(config)# spanning-tree extend system-idSwitch(config)#Related Commands
spanning-tree guard
To enable root guard, use the spanning-tree guard command. To disable root guard, use the no form of this command.
spanning-tree guard {loop | root | none}
no spanning-tree guard
Syntax Description
loop
Enables the loop guard mode on the interface.
root
Enables root guard mode on the interface.
none
Sets the guard mode to none.
Defaults
Root guard is disabled.
Command Modes
Interface configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
12.1(12c)EW
Loop guard support was added.
Examples
This example shows how to enable root guard:
Switch(config-if)# spanning-tree guard rootSwitch(config-if)#Related Commands
spanning-tree link-type
To configure a link type for a port, use the spanning-tree link-type command. To return to the default settings, use the no form of this command.
spanning-tree link-type {point-to-point | shared}
no spanning-tree link-type
Syntax Description
point-to-point
Specifies that the interface is a point-to-point link.
shared
Specifies that the interface is a shared medium.
Defaults
Link type is derived from the duplex mode.
Command Modes
Interface configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
RSTP+ fast transition works only on point-to-point links between two bridges.
By default, the switch derives the link type of a port from the duplex mode. A full-duplex port is considered as a point-to-point link while a half-duplex configuration is assumed to be on a shared link.
If you designate a port as a shared link, RSTP+ fast transition is forbidden, regardless of the duplex setting.
Examples
This example shows how to configure the port as a shared link:
Switch(config-if)# spanning-tree link-type sharedSwitch(config-if)#Related Commands
show spanning-tree interface
spanning-tree loopguard default
To enable loop guard as the default on all ports of a specific bridge, use the spanning-tree loopguard default command. To disable loop guard, use the no form of this command.
spanning-tree loopguard default
no spanning-tree loopguard default
Syntax Description
This command has no keywords or arguments.
Defaults
Loop guard is disabled.
Command Modes
Global configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
Loop guard provides an additional security in the bridge network. Loop guard prevents alternate or root ports from becoming the designated port because of a failure leading to a unidirectional link.
Loop guard operates only on ports that are considered point-to-point by the spanning tree.
Individual loop-guard port configuration overrides this global default.
Examples
This example shows how to enable loop guard:
Switch(config)# spanning-tree loopguard defaultSwitch(config)#Related Commands
show spanning-tree
spanning-tree guardspanning-tree mode
To switch between PVST+ and MST modes, use the spanning-tree mode command. To return to the default settings, use the no form of this command.
spanning-tree mode {pvst | mst | rapid-pvst}
no spanning-tree mode {pvst | mst | rapid-pvst}
Syntax Description
Defaults
PVST+ mode
Command Modes
Configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
12.1(19)EW
Support for the rapid-pvst keyword.
Usage Guidelines
Caution
Examples
This example shows how to switch to MST mode:
Switch(config)# spanning-tree mode mstSwitch(config)#This example shows how to return to the default mode (PVST):
Switch(config)# no spanning-tree modeSwitch(config)#Related Commands
spanning-tree mst
To set the path cost and port-priority parameters for any MST instance (including the CIST with instance ID 0), use the spanning-tree mst command. To return to the default settings, use the no form of this command.
spanning-tree mst instance-id [cost cost] | [port-priority prio]
no spanning-tree mst instance-id {cost | port-priority}
Syntax Description
Defaults
Port priority is 128.
Command Modes
Interface configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
The higher cost cost values indicate higher costs. When entering the cost value, do not include a comma in the entry; for example, enter 1000, not 1,000.
The higher port-priority prio values indicate smaller priorities.
By default, the cost depends on the port speed; faster interface speeds indicate smaller costs. MST always uses long path costs.
Examples
This example shows how to set the interface path cost:
Switch(config-if)# spanning-tree mst 0 cost 17031970Switch(config-if)#This example shows how to set the interface priority:
Switch(config-if)# spanning-tree mst 0 port-priority 64Switch(config-if)#Related Commands
show spanning-tree mst
spanning-tree port-priorityspanning-tree mst configuration
To enter the MST configuration submode, use the spanning-tree mst configuration command. To return to the default MST configuration, use the no form of this command.
spanning-tree mst configuration
no spanning-tree mst configuration
Syntax Description
This command has no arguments or keywords.
Defaults
The default settings are as follows:
•
•
•
•
Command Modes
Global configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
The MST configuration consists of three main parameters:
•
•
•
By default, the value for the MST configuration is the default value for all its parameters.
The abort and exit commands allow you to exit the MST configuration submode. The difference between the two commands depends on whether you want to save your changes or not.
The exit command commits all the changes before leaving MST configuration submode. If you do not map the secondary VLANs to the same instance as the associated primary VLAN, when you exit the MST configuration submode, a message displays and lists the secondary VLANs that are not mapped to the same instance as the associated primary VLAN. The message is as follows:
These secondary vlans are not mapped to the same instance as their primary:->3The abort command leaves the MST configuration submode without committing any changes.
Whenever you change an MST configuration submode parameter, it can cause a loss of connectivity. To reduce the number of service disruptions, when you enter the MST configuration submode, you are changing a copy of the current MST configuration. When you are done editing the configuration, you can apply all the changes at once by using the exit keyword, or you can exit the submode without committing any change to the configuration by using the abort keyword.
In the unlikely event that two users enter a new configuration at exactly at the same time, this message is displayed:
Switch(config-mst)# exit% MST CFG:Configuration change lost because of concurrent accessSwitch(config-mst)#Examples
This example shows how to enter the MST configuration submode:
Switch(config)# spanning-tree mst configurationSwitch(config-mst)#This example shows how to reset the MST configuration to the default settings:
Switch(config)# no spanning-tree mst configurationSwitch(config)#Related Commands
instance
name
revision
show spanning-tree mstspanning-tree mst forward-time
To set the forward delay timer for all the instances, use the spanning-tree mst forward-time command. To return to the default settings, use the no form of this command.
spanning-tree mst forward-time seconds
no spanning-tree mst forward-time
Syntax Description
seconds
Number of seconds to set the forward delay timer for all the instances on the Catalyst 4500 series switch; valid values are from 4 to 30 seconds.
Defaults
The forward delay timer is set for 15 seconds.
Command Modes
Global configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Examples
This example shows how to set the forward-delay timer:
Switch(config)# spanning-tree mst forward-time 20Switch(config)#Related Commands
spanning-tree mst hello-time
To set the hello-time delay timer for all the instances, use the spanning-tree mst hello-time command. To return to the default settings, use the no form of this command.
spanning-tree mst hello-time seconds
no spanning-tree mst hello-time
Syntax Description
seconds
Number of seconds to set the hello-time delay timer for all the instances on the Catalyst 4500 series switch; valid values are from 1 to 10 seconds.
Defaults
The hello-time delay timer is set for 2 seconds.
Command Modes
Global configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
If you do not specify the hello-time value, the value is calculated from the network diameter.
Examples
This example shows how to set the hello-time delay timer:
Switch(config)# spanning-tree mst hello-time 3Switch(config)#Related Commands
spanning-tree mst max-age
To set the max-age timer for all the instances, use the spanning-tree mst max-age command. To return to the default settings, use the no form of this command.
spanning-tree mst max-age seconds
no spanning-tree mst max-age
Syntax Description
seconds
Number of seconds to set the max-age timer for all the instances on the Catalyst 4500 series switch; valid values are from 6 to 40 seconds.
Defaults
The max-age timer is set for 20 seconds.
Command Modes
Global configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Examples
This example shows how to set the max-age timer:
Switch(config)# spanning-tree mst max-age 40Switch(config)#Related Commands
spanning-tree mst max-hops
To specify the number of possible hops in the region before a BPDU is discarded, use the spanning-tree mst max-hops command. To return to the default settings, use the no form of this command.
spanning-tree mst max-hops hopnumber
no spanning-tree mst max-hops
Syntax Description
hopnumber
Number of possible hops in the region before a BPDU is discarded; valid values are from 1 to 40 hops.
Defaults
Number of hops is 20.
Command Modes
Global configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Examples
This example shows how to set the number of possible hops in the region before a BPDU is discarded to 25:
Switch(config)# spanning-tree mst max-hops 25Switch(config)#Related Commands
spanning-tree mst root
To designate the primary root, secondary root, bridge priority, and timer value for an instance, use the spanning-tree mst root command. To return to the default settings, use the no form of this command.
spanning-tree mst instance-id root {primary | secondary} | {priority prio} [diameter dia [hello-time hello]]
no spanning-tree mst root
Syntax Description
Defaults
Bridge priority is 32768.
Command Modes
Global configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
The bridge priority can be set in increments of 4096 only. When you set the priority, valid values are 0, 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768, 36864, 40960, 45056, 49152, 53248, 57344, and 61440.
You can set the priority to 0 to make the switch root.
The spanning-tree root secondary bridge priority value is 16384.
The diameter dia and hello-time hello options are available for instance 0 only.
If you do not specify the hello_time value, the value is calculated from the network diameter.
Examples
This example shows how to set the bridge priority:
Switch(config)# spanning-tree mst 0 root priority 4096Switch(config)#This example shows how to set the priority and timer values for the bridge:
Switch(config)# spanning-tree mst 0 root primary diameter 7 hello-time 2Switch(config)# spanning-tree mst 5 root primarySwitch(config)#Related Commands
spanning-tree pathcost method
To set the path cost calculation method, use the spanning-tree pathcost method command. To revert to the default setting, use the no form of this command.
spanning-tree pathcost method {long | short}
no spanning-tree pathcost method
Syntax Description
long
Specifies 32-bit-based values for port path costs.
short
Specifies 16-bit-based values for port path costs.
Defaults
Port path cost has 32-bit-based values.
Command Modes
Global configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
This command applies to all the spanning-tree instances on the switch.
The long path cost calculation method uses all the 32 bits for path cost calculation and yields values in the range of 1 through 200,000,000.
The short path cost calculation method (16 bits) yields values in the range of 1 through 65,535.
Examples
This example shows how to set the path cost calculation method to long:
Switch(config) spanning-tree pathcost method longSwitch(config)This example shows how to set the path cost calculation method to short:
Switch(config) spanning-tree pathcost method shortSwitch(config)Related Commands
spanning-tree portfast (interface configuration mode)
To enable PortFast mode, where the interface is immediately put into the forwarding state upon linkup without waiting for the timer to expire, use the spanning-tree portfast command. To return to the default setting, use the no form of this command.
spanning-tree portfast {disable | trunk}
no spanning-tree portfast
Syntax Description
disable
Disables PortFast on the interface.
trunk
Enables PortFast on the interface even while in the trunk mode.
Defaults
PortFast mode is disabled.
Command Modes
Interface configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
12.1(12c)EW
The disable and trunk options were added.
Usage Guidelines
You should use this feature only with interfaces that connect to end stations; otherwise, an accidental topology loop could cause a data packet loop and disrupt the Catalyst 4500 series switch and network operation.
An interface with PortFast mode enabled is moved directly to the spanning-tree forwarding state when linkup occurs without waiting for the standard forward-time delay.
Be careful when using the no spanning-tree portfast command. This command does not disable PortFast if the spanning-tree portfast default command is enabled.
This command has four states:
•
•
•
Note
•
