Table Of Contents
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
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
udld (global configuration mode)
udld (interface configuration mode)
vtp (global configuration mode)
22spanning-tree backbonefast
To enable BackboneFast on a spanning tree VLAN, use the spanning-tree backbonefast command. To disable BackboneFast, use the no form of the command.
spanning-tree backbonefast
no spanning-tree backbonefast
Syntax Description
This command has no arguments or keywords.
Defaults
Spanning-tree 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 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
BPDU filtering 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
CautionUse care when entering the spanning-tree bpdufilter enable command. Enabling BPDU filtering on an interface is approximately equivalent to disabling the spanning tree for this interface. It is possible to create bridging loops if this command is not correctly used.
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:
•
•
•
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 error-disabled state as a protective measure. This command has three states:
•
•
•
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 cost 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 value, higher values indicate higher costs. The range applies regardless of the protocol type specified. Path cost is calculated based on interface bandwidth.
Examples
This example shows how to access an interface and set a path cost value of 250 for the spanning tree VLAN 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 error 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 interfaces status
show etherchannel
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 root 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
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
This command is not supported on systems configured with a Supervisor Engine 1.
RSTP+ fast transition only works 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 disallowed, 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 only operates 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}
no spanning-tree mode
Syntax Description
Defaults
PVST+ mode is enabled.
Command Modes
Global configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
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
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
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.
Higher port-priority prio values indicate smaller priorities.
By default, 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
This command has no default settings.
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 default MST configuration parameters are as follows:
•
•
•
•
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 secondary VLANs to the same instance as the associated primary VLAN, when you exit the MST configuration submode, a warning message displays and lists the secondary VLANs that are not mapped to the same instance as the associated primary VLAN. The warning 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 warning 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 the 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
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 the 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 switch; valid values are from 1 to 10 seconds.
Defaults
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 the 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 switch; valid values are from 6 to 40 seconds.
Defaults
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 the 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
20 hops
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-hops:
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 the 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
Spanningtree PortFast 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
•
Examples
This example shows how to enable PortFast mode:
Switch(config-if)# spanning-tree portfastSwitch(config-if)Related Commands
spanning-tree cost
spanning-tree port-priority
spanning-tree portfast default
spanning-tree uplinkfast
spanning-tree vlan
show spanning-treespanning-tree portfast bpdufilter default
To enable the BPDU filtering by default on all PortFast ports, use the spanning-tree portfast bpdufilter default command. To return to the default settings, use the no form of this command.
spanning-tree portfast bpdufilter default
no spanning-tree portfast bpdufilter default
Syntax Description
This command has no keywords or arguments.
Defaults
BPDU filtering 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
The spanning-tree portfast bpdufilter command enables BPDU filtering globally on the Catalyst 4500 series switch. BPDU filtering prevents a port from sending or receiving any BPDUs.
You can override the effects of the portfast bpdufilter default command by configuring BPDU filtering at the interface level.
Note
When enabled locally on a port, BPDU filtering prevents the Catalyst 4500 series switch from receiving or sending BPDUs on this port.
Caution
Examples
This example shows how to enable BPDU filtering by default:
Switch(config)# spanning-tree portfast bpdufilter defaultSwitch(config)#Related Commands
show spanning-tree mst
spanning-tree bpdufilterspanning-tree portfast bpduguard default
To enable the BPDU guard feature by default on all PortFast ports, use the spanning-tree portfast bpduguard default command. To return to the default settings, use the no form of this command.
spanning-tree portfast bpduguard default
no spanning-tree portfast bpduguard default
Syntax Description
This command has no keywords or arguments.
Defaults
BPDU 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
Caution
BPDU guard disables a port if it receives a BPDU. BPDU guard is applied only on ports that are PortFast enabled and are in an operational PortFast state.
Examples
This example shows how to enable BPDU guard by default:
Switch(config)# spanning-tree portfast bpduguard defaultSwitch(config)#Related Commands
show spanning-tree mst
spanning-tree bpduguardspanning-tree portfast default
To globally enable PortFast by default on all access ports, use the spanning-tree portfast default command. To disable PortFast as default on all access ports, use the no form of this command.
spanning-tree portfast default
no spanning-tree portfast default
Syntax Description
This command has no arguments or keywords.
Defaults
PortFast 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
Caution
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.
You can enable PortFast mode on individual interfaces using the spanning-tree portfast (interface configuration mode) command.
Examples
This example shows how to globally enable PortFast by default on all access ports:
Switch(config)# spanning-tree portfast defaultSwitch(config)#Related Commands
show spanning-tree
spanning-tree portfast (interface configuration mode)spanning-tree port-priority
To prioritize an interface when two bridges compete for position as the root bridge, use the spanning-tree port-priority command. The priority you set breaks the tie. To revert to the default setting, use the no form of this command.
spanning-tree port-priority port_priority
no spanning-tree port-priority
Syntax Description
Defaults
Port priority value is 128.
Command Modes
Interface configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Examples
This example shows how to increase the frequency that the spanning tree instance 20 will be chosen as the root-bridge on interface FastEthernet 2/1:
Switch(config-if)# spanning-tree port-priority 0Switch(config-if)#Related Commands
spanning-tree cost
spanning-tree portfast default
spanning-tree portfast (interface configuration mode)
spanning-tree uplinkfast
spanning-tree vlan
show spanning-treespanning-tree uplinkfast
To enable the UplinkFast feature, use the spanning-tree uplinkfast command. To disable UplinkFast, use the no form of the command.
spanning-tree uplinkfast [max-update-rate packets-per-second]
no spanning-tree uplinkfast [max-update-rate]
Syntax Description
max-update-rate packets_per_second
(Optional) Specifies the maximum rate (in packets per second) at which update packets are sent; valid values are from 0 to 65,535.
Defaults
150 packets per second.
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 should be used only on access switches.
When UplinkFast is configured, the bridge priority is changed to 49,152 so that this switch will not be selected as root. All interface path costs of all spanning tree interfaces belonging to the specified spanning tree instances are also increased by 3000.
When spanning tree detects that the root interface has failed, the UplinkFast feature causes an immediate switchover to an alternate root interface, transitioning the new root interface directly to FORWARDING state. During this time, a topology change notification is sent. To minimize the disruption caused by the topology change, a multicast packet is sent to 01-00-0C-CD-CD-CD for each station address in the forwarding bridge except for those associated with the old root interface.
Use the spanning-tree uplinkfast max-update-rate command to enable UplinkFast (if not already enabled) and change the rate at which update packets are sent. Use the no form of the command to return the default rate of 150 pps.
Examples
This example shows how to enable UplinkFast and set the maximum rate to 200 pps:
Switch(config)# spanning-tree uplinkfastSwitch(config)# spanning-tree uplinkfast max-update-rate 200Related Commands
spanning-tree cost
spanning-tree port-priority
spanning-tree portfast default
spanning-tree portfast (interface configuration mode)
spanning-tree vlanspanning-tree vlan
To configure STP on a per-VLAN basis, use the spanning-tree vlan command. To return to the default value, use the no form of this command.
spanning-tree vlan vlan_id [forward-time seconds | hello-time seconds | max-age seconds | priority priority | protocol protocol | root {primary | secondary} [diameter net-diameter [hello-time seconds]]]
no spanning-tree vlan vlan_id [forward-time | hello-time | max-age | priority | root]
Syntax Description
Defaults
The default settings are as follows:
•
•
•
•
•
Command Modes
Global configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
12.1(12c)EW
Support for extended addressing was added.
Usage Guidelines
When you are setting the max-age seconds value, if a bridge does not hear BPDUs from the root bridge within the specified interval, it assumes that the network has changed and recomputes the spanning tree topology.
The spanning-tree root primary alters the switch bridge priority to 8192. If you enter the spanning-tree root primary command and the switch does not become root, then the bridge priority is changed to 100 less than the bridge priority of the current bridge. If the switch does not become root, an error will result.
The spanning-tree root secondary alters the switch bridge priority to 16384. If the root switch fails, this switch becomes the next root switch.
Use the spanning-tree root commands on backbone switches only.
Examples
This example shows how to enable spanning tree on VLAN 200:
Switch(config)# spanning-tree vlan 200Switch(config)#This example shows how to configure the switch as the root switch for VLAN 10 with a network diameter of 4:
Switch(config)# spanning-tree vlan 10 root primary diameter 4Switch(config)#This example shows how to configure the switch as the secondary root switch for VLAN 10 with a network diameter of 4:
Switch(config)# spanning-tree vlan 10 root secondary diameter 4Switch(config)#Related Commands
spanning-tree cost
spanning-tree port-priority
spanning-tree portfast default
spanning-tree portfast (interface configuration mode)
spanning-tree uplinkfast
show spanning-treespeed
To configure the interface speed, use the speed command. To disable a speed setting, use the no form of this command.
speed [10 | 100 | 1000 | auto | nonegotiate]
no speed
Syntax Description
Defaults
See Table 2-21 for a list of default settings.
Command Modes
Interface configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
Table 2-21 lists the supported command options by interface.
If you configure the interface speed and duplex commands manually and enter a value other than speed auto (for example, 10 or 100 Mbps), be sure that you configure the connecting interface speed command to a matching speed but do not use the auto parameter.
When manually configuring the interface speed to either 10 or 100 Mbps, the switch prompts you to also configure duplex mode on the interface.
Note
Caution
Table 2-22 describes the system's performance for different combinations of the duplex and speed modes. The specified duplex command configured with the specified speed command produces the resulting system action.
This example shows how to configure the interface to transmit at 100 Mbps:
Switch(config-if)# speed 100Switch(config-if)#Related Commands
duplex
interface (refer to Cisco IOS documentation)
show controllers (refer to Cisco IOS documentation)
show interfaces (refer to Cisco IOS documentation)switchport
To modify the switching characteristics of a Layer 2 switch interface, use the switchport command. To return the interface to the routed-interface status and erase all further Layer 2 configuration, use the no form of this command without parameters.
switchport [access vlan vlan_num] | [nonegotiate] | [voice vlan {vlan_id | dot1p | none | untagged}]
no switchport [access | nonegotiate | voice vlan]
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.
12.1(11)EW
Support for voice VLAN was added.
Usage Guidelines
The no switchport command shuts the port down and then reenables it, which may generate messages on the device to which the port is connected.
The no form of the switchport access command resets the access mode VLAN to the appropriate default VLAN for the device. The no form of the switchport nonegotiate command removes nonegotiate status.
When you are using the nonegotiate keyword, DISL/DTP negotiation packets will not be sent on the interface. The device will trunk or not trunk according to the mode parameter given: access or trunk. This command will return an error if you attempt to execute it in dynamic (auto or desirable) mode.
The voice VLAN is automatically set to VLAN 1 unless you use one of the optional keywords.
If you use the switch port voice vlan command for an interface, the interface cannot join a port channel.
When you use the switchport voice vlan command the output for the show running-config command changes to show the voice VLAN set.
Examples
This example shows how to cause the port interface to cease operating as a Cisco-routed port and convert to a Layer 2-switched interface:
Switch(config-if)# switchportSwitch(config-if)#This example shows how to cause a port interface in access mode, configured as a switched interface, to operate in VLAN 2:
Switch(config-if)# switchport access vlan 2Switch(config-if)#This example shows how to cause a port interface, configured as a switched interface, to refrain from negotiating trunking mode and act as a trunk or access port (depending on the mode set):
Switch(config-if)# switchport nonegotiateSwitch(config-if)#This example shows how to set the voice VLAN for the interface to VLAN 2:
Switch(config-if)#switchport voice vlan 2switchport voice vlan 2Switch(config-if)#Related Commands
switchport access vlan
To set the VLAN when an interface is in access mode, use the switchport access vlan command. To reset the access mode VLAN to the appropriate default VLAN for the device, use the no form of this command.
switchport access vlan vlan-id
no switchport access vlan
Syntax Description
Defaults
Access VLAN and trunk interface native VLAN are default VLANs corresponding to the platform or interface hardware; all VLAN lists include all VLANs.
Command Modes
Interface configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
You must enter the switchport command without any keywords to configure the LAN interface as a Layer 2 interface before you can enter the switchport access vlan command. This action is required only if you have not entered the switchport command already for the interface.
Entering the no switchport command shuts the port down and then reenables it, which may generate messages on the device to which the port is connected.
The no form of the switchport access vlan command resets the access mode VLAN to the appropriate default VLAN for the device.
If your system is configured with a Supervisor Engine 1, valid values for vlan-id are from 1 to 1005. If your system is configured with a Supervisor Engine 2, valid values for vlan-id are from 1 to 4094. Extended-range VLANs are not supported on systems configured with a Supervisor Engine 1.
Examples
This example shows how to cause the port interface to cease operating as a Cisco-routed port and convert to a Layer 2-switched interface:
Switch(config-if)# switchportSwitch(config-if)#
Note
This example shows how to cause a port interface that has already been configured as a switched interface to operate in VLAN 2 instead of the platform's default VLAN when in access mode:
Switch(config-if)# switchport access vlan 2Switch(config-if)#Related Commands
switchport mode
To set the interface type, use the switchport mode command. To reset the mode to the appropriate default mode for the device, use the no form of the command.
switchport mode {access | trunk | dynamic {auto | desirable}}
switchport mode private-vlan {host | promiscuous | trunk}
no switchport mode
no switchport mode private-vlan
Syntax Description
Defaults
Trunk link
Command Modes
Interface configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
If you enter access mode, the interface goes into permanent nontrunking mode and negotiates to convert the link into a nontrunk link even if the neighboring interface does not agree to the change.
If you enter trunk mode, the interface goes into permanent trunking mode and negotiates to convert the link into a trunk link even if the neighboring interface does not agree to the change.
If you enter dynamic auto mode, the interface converts the link to a trunk link if the neighboring interface is set to trunk or desirable mode.
If you enter dynamic desirable mode, the interface becomes a trunk interface if the neighboring interface is set to trunk, desirable, or auto mode.
The port becomes inactive if you configure it as a private VLAN trunk port and one of the following applies:
•
•
Similarly, if a private port PVLAN association or mapping is deleted, or if a private port is configured as a SPAN destination, it becomes inactive.
Examples
This example shows how to set the interface to dynamic desirable mode:
Switch(config-if)# switchport mode dynamic desirableSwitch(config-if)#This example shows how to set a port to PVLAN host mode:
Switch(config-if)# switchport mode private-vlan hostSwitch(config-if)#This example shows how to set a port to private VLAN trunk:
Switch(config-if)# switchport mode private-vlan trunkSwitch(config-if)#Related Commands
show interfaces switchport
switchport
switchport private-vlan host-association
switchport private-vlan mappingswitchport private-vlan association trunk
To configure the association between a secondary VLANs and a VLAN on a private VLAN trunk port, use the switchport private-vlan association trunk command. To remove the PVLAN mapping from the port, use the no form of the command.
switchport private-vlan association trunk {primary-vlan-id} {secondary-vlan-id}
no switchport private-vlan association trunk {primary-vlan-id}
Syntax Description
primary-vlan-id
Number of the primary VLAN of the private VLAN relationship.
secondary-vlan-id
Number of the secondary VLAN of the private VLAN relationship.
Defaults
Private VLAN mapping 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
Multiple private VLAN pairs can be specified so that a private VLAN trunk port can carry multiple secondary VLANs. If an association is specified for the existing primary VLAN, the existing association is replaced.
If there is no trunk association, any packets received on secondary VLANs are dropped.
Examples
This example shows how to configure a port with a primary VLAN (VLAN 18) and secondary VLAN (VLAN 20):
Switch(config-if)# switchport private-vlan association trunk 18 20Switch(config-if)#This example shows how to remove the PVLAN association from the port:
Switch(config-if)# no switchport private-vlan association trunk 18Switch(config-if)#Related CommandsSwitch(config-if)#
show interfaces switchport
switchport modeswitchport private-vlan host-association
To define a PVLAN association for an isolated or community port, use the switchport private-vlan host-association command. To remove the PVLAN mapping from the port, use the no form of the command.
switchport private-vlan host-association {primary-vlan-id} {secondary-vlan-id}
no switchport private-vlan host-association
Syntax Description
Defaults
Private VLAN mapping 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
Support for extended addressing was added.
Usage Guidelines
There is no runtime effect on the port unless it is in PVLAN host mode. If the port is in PVLAN host mode but neither of the VLANs exist, the command is allowed, but the port is made inactive.
The secondary VLAN may be an isolated or community VLAN.
Examples
This example shows how to configure a port with a primary VLAN (VLAN 18) and secondary VLAN (VLAN 20):
Switch(config-if)# switchport private-vlan host-association 18 20Switch(config-if)#This example shows how to remove the PVLAN association from the port:
Switch(config-if)# no switchport private-vlan host-associationSwitch(config-if)#Related Commands
show interfaces switchport
switchport modeswitchport private-vlan mapping
To define private VLAN mapping for a promiscuous port, use the switchport private-vlan mapping command. To clear all mapping from the private VLAN, use the no form of this command.
switchport private-vlan mapping {primary-vlan-id} {secondary-vlan-list} | {add secondary-vlan-list} | {remove secondary-vlan-list}
no switchport private-vlan mapping
Syntax Description
Defaults
No PVLAN mappings are defined.
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
Support for extended addressing was added.
Usage Guidelines
There is no runtime effect on the port unless it is in PVLAN promiscuous mode. If the port is in PVLAN promiscuous mode but the VLANs do not exist, the command is allowed, but the port is made inactive.
The secondary VLAN may be an isolated or community VLAN.
Examples
This example shows how to configure the mapping of primary VLAN 18 to secondary isolated VLAN 20 on a port:
Switch(config-if)# switchport private-vlan mapping 18 20Switch(config-if)#This example shows how to add a VLAN to the mapping:
Switch(config-if)# switchport private-vlan mapping 18 add 21Switch(config-if)#Related Commands
show interfaces private-vlan mapping
switchport private-vlan trunk allowed vlan
To configure a list of allowed normal VLANs on a private VLAN trunk port, use the switchport private-vlan trunk allowed vlan command. To remove all allowed normal VLANs from a private VLAN trunk port, use the no form of the command.
switchport private-vlan trunk allowed vlan {vlan-list} all | none | [add | remove | except] vlan_atom [,vlan_atom...]
no switchport private-vlan trunk allowed vlan
Syntax Description
Defaults
All allowed normal VLANs are removed from a private VLAN trunk port.
Command Modes
Interface configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
By default, no normal VLANs are allowed unless explicitly configured to be allowed.
Only use this command for normal VLANs on a private VLAN trunk port.
Use the switchport private-vlan association trunk command to configure a port that can carry private VLANs on a private VLAN trunk port.
Examples
This example shows how to configure private VLAN trunk port that carries normal VLANs 1 to10:
Switch(config-if)# switchport private-vlan trunk allowed vlan 1-10Switch(config-if)#This example shows how to remove all allowed normal VLANs from a private VLAN trunk port:
Switch(config-if)# no switchport private-vlan trunk allowed vlanSwitch(config-if)#Related Commands
show interfaces switchport
switchport modeswitchport private-vlan trunk native vlan
To configure a VLAN to which untagged packets (as in IEEE 802.1Q tagging) are assigned on a private VLAN trunk port, use the switchport private-vlan trunk native vlan command. To remove the native VLAN from the private VLAN trunk port, use the no form of the command.
switchport private-vlan trunk native vlan {vlan-id}
no switchport private-vlan trunk native vlan
Syntax Description
Defaults
Native VLAN is removed.
Command Modes
Interface configuration
Command History
12.1(12c)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
If there is no native VLAN configured, all untagged packets are dropped.
If the VLAN is a primary VLAN and the port is configured to be a secondary port, then the untagged packets are dropped.
Examples
This example shows how to configure a port with native VLAN 5:
Switch(config-if)# switchport private-vlan trunk native vlan 5Switch(config-if)#This example shows how to remove the native VLAN from the private VLAN trunk port:
Switch(config-if)# no switchport private-vlan trunk nativeSwitch(config-if)#Related Commands
show interfaces switchport
switchport modeswitchport trunk
To set trunk characteristics when an interface is in trunking mode, use the switchport trunk command. To reset all of the trunking characteristics back to the original defaults, use the no form of this command.
switchport trunk encapsulation {isl | dot1q | negotiate}
no switchport trunk encapsulation
switchport trunk native vlan vlan_id
no switchport trunk native vlan vlan_id
switchport trunk allowed vlan vlan_list
no switchport trunk allowed vlan vlan_list
switchport trunk pruning vlan vlan_list
no switchport trunk pruning vlan vlan_list
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.
12.1(12c)EW
Support for extended addressing was added.
Usage Guidelines
The vlan_list format is all | none | [add | remove | except] vlan_atom[,vlan_atom...], where:
•
•
•
•
•
•
The switchport trunk encapsulation command is supported only for platforms and interface hardware that can support both ISL and 802.1Q formats.
If you enter the negotiate keywords, and DISL and DTP negotiation do not resolve the encapsulation format, ISL is the selected format. The no form of the command resets the trunk encapsulation format back to the default.
The no form of the native vlan command resets the native mode VLAN to the appropriate default VLAN for the device.
The no form of the allowed vlan command resets the list to the default list, which allows all VLANs.
The no form of the pruning vlan command resets the list to the default list, which enables all VLANs for VTP pruning.
The following configuration guidelines and restrictions apply when using 802.1Q trunks and impose some limitations on the trunking strategy for a network. Keep these restrictions and suggestions in mind when using 802.1Q trunks:
•
•
•
•
•
•
•
Examples
This example shows how to cause a port interface configured as a switched interface to encapsulate in 802.1Q trunking format regardless of its default trunking format in trunking mode:
Switch(config-if)# switchport trunk encapsulation dot1qSwitch(config-if)#Related Commands
system mtu
To set the maximum Layer 2 or Layer 3 payload size, use the system mtu command. To revert to the default MTU setting, use the no form of this command.
system mtu datagram-size
no system mtu
Syntax Description
Defaults
1500 bytes
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 datagram-size parameter specifies the Ethernet payload size, not the total Ethernet frame size, and the Layer 3 MTU is changed as a result of changing the system mtu command.
For ports from 3 to18 on linecard model WS-X4418-GB and ports from 1 to 12 on model WS-X4412-2GB-TX, only the standard IEEE Ethernet payload size of 1500 bytes is supported.
For other modules, an Ethernet payload size of up to 1552 bytes is supported, with a total Ethernet frame size of up to 1600 bytes.
Examples
This example shows how to set the MTU size to 1550 bytes:
Switch# conf tEnter configuration commands, one per line. End with CNTL/Z.Switch(config)# system mtu 1550Switch(config)# endSwitch#This example shows how to revert to the default MTU setting:
Switch# conf tEnter configuration commands, one per line. End with CNTL/Z.Switch(config)# no system mtuSwitch(config)# endSwitch#Related Commands
show interface
show system mtutx-queue
To configure the transmit queue parameters for an interface, use the tx-queue command. To return to the default value, use the no form of this command.
tx-queue [queue-id] {bandwidth bandwidth-rate | priority high | shape shape-rate}
no tx-queue
Syntax Description
Defaults
QoS enabled bandwidth-rate is 4:255; QoS disabled bandwidth-rate is 255:1.
Command Modes
Interface configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
The bandwidth and shape rates cannot exceed the maximum speed of the interface.
Bandwidth can be configured only on the following:
•
•
•
•
•
Only transmit queue 3 can be configured to be a high-priority transmit queue.
Examples
This example shows how to allocate bandwidth on queue 1 to 100 MBPS:
Switch(config-if)# tx-queue 1Switch(config-if-tx-queue)# bandwidth 1000000000Switch(config-if-tx-queue)#This example shows how to configure transmit queue 3 to the high priority:
Switch(config-if)# tx-queue 3Switch(config-if-tx-queue)# priority highSwitch(config-if-tx-queue)#This example shows how to configure the traffic shaping rate of 64 kbps to transmit queue 1:
Switch(config-if)# tx-queue 1Switch(config-if-tx-queue)# shape 64000Switch(config-if-tx-queue)#Related Commands
udld (global configuration mode)
To enable aggressive or normal mode in UDLD protocol and to set the configurable message timer time, use the udld command. Use the no form of the command to do the following:
•
•
•
udld enable | aggressive
no udld enable | aggressive
udld message time message-timer-time
no udld message time
Syntax Description
Defaults
Mode is disallowed on all fiber interfaces; message time is 15 seconds
Command Modes
Global configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
If you enable aggressive mode, once all the neighbors of a port have aged out either in the advertisement or in the detection phase, UDLD restarts the linkup sequence to try to get resynchronized with any potentially out-of-sync neighbor and shuts down the port if the message train from the link is still undetermined.
This command affects fiber interfaces only. Use the udld (interface configuration mode) command to enable UDLD on other interface types.
Examples
This example shows how to enable UDLD on all fiber interfaces:
Switch (config)# udld enableSwitch (config)#Related Commands
show udld
udld (interface configuration mode)udld (interface configuration mode)
To enable UDLD on an individual interface or to prevent a fiber interface from being enabled by the udld (global configuration mode) command, use the udld command. To return to the udld (global configuration mode) command setting, or if the port is a nonfiber port to disable UDLD, use the no form of this command.
udld {enable | aggressive | disable}
no udld {enable | aggressive | disable}
Syntax Description
enable
Enables UDLD on this interface.
aggressive
Enables UDLD in aggressive mode on this interface.
disable
Disables UDLD on this interface.
Defaults
The defaults 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
If you enable aggressive mode, once all the neighbors of a port have aged out either in the advertisement or in the detection phase, UDLD restarts the linkup sequence to try to get resynchronized with any potentially out-of-sync neighbor and shuts down the port if the message train from the link is still undetermined.
Use the no udld enable command on fiber ports to return control of UDLD to the global udld enable command. On nonfiber ports, use this command to disable UDLD.
Use the udld aggressive command on fiber ports to override the setting of the global udld (enable or aggressive) command. Use the no form on fiber ports to remove this setting and return control of UDLD enabling back to the global udld command. On nonfiber ports, use this command to disable UDLD.
The disable keyword is supported on fiber ports only. Use the no form of this command to remove this setting and return control of UDLD to the udld (global configuration mode) command.
If the port changes from fiber to nonfiber or vice versa, all configurations will be maintained because of a change of module or a GBIC change detected by the platform software.
Examples
This example shows how to cause any port interface to enable UDLD, despite the current global udld (global configuration mode) setting:
Switch (config-if)# udld enableSwitch (config-if)#This example shows how to cause any port interface to enable UDLD in aggressive mode, despite the current global udld (enable or aggressive) setting:
Switch (config-if)# udld aggressiveSwitch (config-if)#This example shows how to cause a fiber port interface to disable UDLD, despite the current global udld (global configuration mode) setting:
Switch (config-if)# udld disableSwitch (config-if)#Related Commands
show udld
udld (global configuration mode)udld reset
To reset all UDLD ports in shut down state, use the udld reset command.
udld reset
Syntax Description
This command has no keywords or variables.
Defaults
This command has no default settings.
Command Modes
Privileged EXEC
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
If the interface configuration is still enabled for UDLD, these ports will begin to run UDLD again; it may shut down for the same reason if the problem has not been corrected.
This command permits traffic to flow on the ports again; other features, such as spanning tree, PAGP, and DTP, behave normally if enabled.
Examples
This example shows how to reset all ports shut down by UDLD:
Switch# udld resetSwitch#Related Commands
username
To establish a username-based authentication system, use the username command.
username name secret {0 | 5} password
Syntax Description
Defaults
No username-based authentication system is established.
Command Modes
Global configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
Use this command to enable Enhanced Password Security for the specified username. This command enables MD5 encryption on the password. MD5 encryption is a strong encryption method that is not retrievable. You cannot use MD5 encryption with protocols that require clear-text passwords, such as CHAP.
This command can be useful for defining usernames that get special treatment. For example, you can use this command to define an "info" username that does not require a password but that connects the user to a general purpose information service.
The username command provides both username and secret authentication for login purposes only.
The name argument can be only one word. White spaces and quotation marks are not allowed.
Multiple username commands can be used to specify options for a single user.
For information about additional username commands, refer to the Cisco IOS Command Reference.
Related Commands
enable password (refer to Cisco IOS documentation)
enable secret (refer to Cisco IOS documentation)
username (refer to Cisco IOS documentation)verify
To verify the checksum of a file on a Flash memory file system, use the verify command.
verify [/md5] [flash-filesystem:] [filename] [expected-md5-signature]
Syntax Description
Defaults
Current working device is specified.
Command Modes
Privileged EXEC
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
Each software image that is distributed on disk uses a single checksum for the entire image. This checksum is displayed only when the image is copied into Flash memory.
The README file, which is included with the image on the disk, lists the name, file size, and checksum of the image. Review the contents of the README file before loading or duplicating the new image so that you can verify the checksum when you copy it into Flash memory or on to a server.
Use the verify /md5 command to verify the MD5 signature of a file before using it. This command validates the integrity of a copied file by comparing a precomputed MD5 signature with the signature computed by this command. If the two MD5 signatures match, the copied file is identical to the original file.
You can find the MD5 signature posted on the Cisco.com page with the image.
You can use the verify /md5 command in one of the following ways:
•
Check the displayed signature against the MD5 signature posted on the Cisco.com page.
•
After completing the comparison, the system returns with a verified message. If an error is detected, the output is similar to the following:
Switch# verify /md5 slot0:c4-jsv-mz 0f.........................................................................................................................................................................................................Done!%Error verifying slot0:c4-jsv-mzComputed signature = 0f369ed9e98756f179d4f29d6e7755d3Submitted signature = 0fTo display the contents of Flash memory, enter the show flash command. The Flash contents listing does not include the checksum of individual files. To recompute and verify the image checksum after the image has been copied into Flash memory, enter the verify command.
A colon (:) is required after the specified device.
Examples
This example shows how to use the verify command:
Switch# verify cat6k_r47_1.cbi..........................................................File cat6k_r47_1.cbi verified OK.Switch#This example shows how to manually check the MD5 signature:
Switch# verify /md5 c4-jsv-mz.................................................................................................................................................................................................................................................................................................Done!verify /md5 (slot0:c4-jsv-mz) = 0f369ed9e98756f179d4f29d6e7755d3Switch#This example shows how to allow the system to compare the MD5 signatures:
Switch# verify /md5 slot0:c4-jsv-mz 0f369ed9e98756f179d4f29d6e7755d3.................................................................................................................................................................................................................................................................................................Done!verified /md5 (slot0:c6sup12-jsv-mz) = 0f369ed9e98756f179d4f29d6e7755d3Switch#Related Commands
show file system (Flash file system) (refer to Cisco IOS documentation)
show flash (refer to Cisco IOS documentation)
vlan (VLAN database mode)
To configure a specific VLAN, use the vlan command. To delete a VLAN, use the no form of this command.
vlan vlan_id [are hops] [backupcrf mode] [bridge type | bridge-num] [media type] [mtu mtu-size] [name vlan-name] [parent parent-vlan-id] [ring ring-number] [said said-value] [state {suspend | active}] [stp type type] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]
no vlan vlan
Syntax Description
Defaults
The defaults are as follows:
•
•
•
•
•
–
–
–
–
•
•
•
•
•
Command Modes
VLAN configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
VLAN 1 parameters are factory configured and cannot be changed.
When you define vlan-name, the name must be unique within the administrative domain.
The SAID is documented in 802.10. When the no form is used, the VLANs SAID is returned to the default.
When you define the said-value, the name must be unique within the administrative domain.
The bridge bridge-number argument is used only for Token Ring-net and FDDI-net VLANs and is ignored in other types of VLANs. When the no form is used, the VLANs source-route bridging number returns to the default.
The parent VLAN resets to the default if the parent VLAN is deleted or the media keyword changes the VLAN type or the VLAN type of the parent VLAN.
The tb-vlan1 and tb-vlan2 are used to configure translational bridge VLANs of a specified type of VLAN and are not allowed in other types of VLANs. Translational bridge VLANs must be a different VLAN type than the affected VLAN; if two VLANs are specified, the two must be different VLAN types.
A translational bridge VLAN will reset to the default if the translational bridge VLAN is deleted or the media keyword changes the VLAN type or the VLAN type of the corresponding translational bridge VLAN.
Examples
This example shows how to add a new VLAN with all default parameters to the new VLAN database:
Switch(vlan)# vlan 2
Note
This example shows how to cause the device to add a new VLAN, specify the media type and parent VLAN ID number 3, and set all other parameters to the defaults:
Switch(vlan)# vlan 2 media fastethernet parent 3VLAN 2 modified:Media type FASTETHERNETParent VLAN 3This example shows how to delete VLAN 2:
Switch(vlan)# no vlan 2Switch(vlan)#This example shows how to return the MTU to the default for its type and the translational bridging VLANs to the default:
Switch(vlan)# no vlan 2 mtu tb-vlan1 tb-vlan2Switch(vlan)#Related Commands
vlan access-map
To enter the VLAN access-map command mode to create a VLAN access map, use the vlan access-map command. To remove a mapping sequence or the entire map, use the no form of this command.
vlan access-map name [seq#]
no vlan access-map name [seq#]
Syntax Description
Defaults
This command has no default settings.
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 enter the sequence number of an existing map sequence, you enter VLAN access-map mode. If you do not specify a sequence number, a number is automatically assigned. You can enter one match clause and one action clause per map sequence. If you enter the no vlan access-map name [seq#] command without entering a sequence number, the whole map is removed. Once you enter VLAN access-map mode, the following commands are available:
•
•
•
•
•
•
Examples
This example shows how to enter the VLAN access-map mode:
Switch(config)# vlan access-map ciscoSwitch(config-access-map)#Related Commands
vlan database
To enter VLAN configuration mode, use the vlan database command.
vlan database
Syntax Description
This command has no arguments or keywords.
Defaults
This command has no default settings.
Command Modes
Privileged EXEC
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
From VLAN configuration mode, you can access the following VLAN database editing buffer manipulation commands:
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Examples
This example shows how to enter VLAN configuration mode:
Switch# vlan databaseSwitch(vlan)#This example shows how to exit VLAN configuration mode without applying changes after you are in VLAN configuration mode:
Switch(vlan)# abortAborting....Switch#This example shows how to delete a VLAN after you are in VLAN configuration mode:
Switch(vlan)# no vlan 100Deleting VLAN 100...Switch(vlan)#This example shows how to turn off pruning after you are in VLAN configuration mode:
Switch(vlan)# no vtp pruningPruning switched OFFSwitch(vlan)#Related Commands
vlan filter
To apply a VLAN access map, use the vlan filter command. To clear the VLAN access maps from VLANs or interfaces, use the no form of this command.
vlan filter map-name {vlan-list vlan-list}
no vlan filter map-name {vlan-list [vlan-list]}
Syntax Description
map-name
VLAN access-map tag.
vlan-list
vlan-listVLAN list; see "Usage Guidelines" for valid values.
Defaults
This command has no default settings.
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 your system is configured with a Supervisor Engine 1, valid values for vlan-id are from 1 to 1005. If your system is configured with a Supervisor Engine 2, valid values for vlan-id are from 1 to 4094. Extended-range VLANs are not supported on systems configured with a Supervisor Engine 1.
When configuring an action clause in a VLAN access map, note the following:
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When entering the no form of this command, the vlan-list parameter is optional (but the keyword vlan-list is required). If you do not enter the vlan-list parameter, the VACL is removed from all VLANs where the map-name parameter is applied.
Examples
This example shows how to apply a VLAN access map on VLANs 7 through 9:
Switch(config)# vlan filter ganymede vlan-list 7-9Switch(config)#Related Commands
vtp (global configuration mode)
To modify the name of a VTP configuration storage file, use the vtp command. To clear a filename, use the no form of this command.
vtp {{file filename} | {if-id name}}
no vtp {{file filename} | {if-id name}}
Syntax Description
Defaults
Filenames are not modified.
Command Modes
Global configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
You cannot use the vtp file command to load a new database. You can use it only to rename the file in which the existing database is stored.
You can use the vtp if-id command to specify the name of the interface providing the VTP updater ID for this device. The VTP updater is the device that adds, deletes, or modifies VLANs to a network, and triggers a VTP updater to inform the rest of the system of the changes.
Examples
This example shows how to specify the IFS file system file where VTP configuration is stored:
Switch(config)# vtp file vtpconfigSetting device to store VLAN database at filename vtpconfig.Switch(config)#This example shows how to specify the name of the interface providing the VTP updater ID:
Switch(config)# vtp if-id fastethernetSwitch(config)#Related Commands
vtp client
To place a device in VTP client mode, use the vtp client command. To return to VTP server mode, use the no form of this command.
vtp client
no vtp client
Syntax Description
This command has no arguments or keywords.
Defaults
VTP server mode
Command Modes
VLAN configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
If the receiving switch is in client mode, the client switch changes its configuration to duplicate the configuration of the server. If you have switches in client mode, make sure to make all VTP or VLAN configuration changes on a switch in server mode.
The vtp server command is the functional equivalent of no vtp client except that it does not return an error if the device is not in client mode.
Examples
This example shows how to place the device in VTP client mode:
Switch(vlan-config)# vtp clientSwitch(vlan-config)#Related Commands
show vtp
vtp (global configuration mode)vtp domain
To configure the administrative domain name for a device, use the vtp domain command.
vtp domain domain-name
Syntax Description
Defaults
This command has no default settings.
Command Modes
VLAN configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
Domain names are case sensitive.
Until a domain name is set, the device is in the no-management-domain state. In this state, the device does not transmit any VTP advertisements regardless of changes to local VLAN configuration. The device leaves the no-management-domain state upon receiving the first VTP summary packet on any port that is currently trunking or upon configuration of a domain name using the vtp domain command. If the device receives its domain from a summary packet, it resets its configuration revision number to zero. Once the device leaves the no-management-domain state, it can never be configured to reenter the number except by cleaning NVRAM and reloading.
Examples
This example shows how to set the devices administrative domain:
Switch(vlan-config)# vtp domain DomainChandonSwitch(vlan-config)#Related Commands
show vtp
vtp (global configuration mode)vtp password
To create a VTP domain password, use the vtp password command. To delete the password, use the no form of this command.
vtp password password-value
no vtp password
Syntax Description
password-value
An ASCII string, from 1 to 32 characters, identifying the administrative domain for the device.
Defaults
No password
Command Modes
VLAN configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Examples
This example shows how to create a VTP domain password:
Switch(vlan-config)# vtp password DomainChandonSwitch(vlan-config)#This example shows how to delete the VTP domain password:
Switch(vlan-config)# no vtp passwordClearing device VLAN database password.Switch(vlan-config)#Related Commands
show vtp
vtp (global configuration mode)vtp pruning
To enable pruning in the VLAN database, use the vtp pruning command. To disable pruning in the VLAN database, use the no form of this command.
vtp pruning
no vtp pruning
Syntax Description
This command has no arguments or keywords.
Defaults
Prunning is disabled.
Command Modes
VLAN configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
VTP pruning causes information about each pruning-eligible VLAN to be removed from VTP updates if there are no stations belonging to that VLAN.
Examples
This example shows how to enable pruning in the VLAN database:
Switch(vlan-config)# vtp pruningPruning switched ONSwitch(vlan-config)#This example shows how to disable pruning in the VLAN database:
Switch(vlan-config)# no vtp pruningPruning switched OFFSwitch(vlan-config)#Related Commands
show vtp
vtp (global configuration mode)vtp server
To place the device in VTP server mode, use the vtp server command.
vtp server
Syntax Description
This command has no arguments or keywords.
Defaults
This command has no default settings.
Command Modes
VLAN configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
If you make a change to the VTP or VLAN configuration on a switch in server mode, that change is propagated to all the switches in the same VTP domain.
VTP can be set to either server or client mode only when dynamic VLAN creation is disabled.
If the receiving switch is in server mode, the configuration is not changed.
The vtp server command is the functional equivalent of no vtp client except that it does not return an error if the device is not in client mode.
Examples
This example shows how to place the device in VTP server mode:
Switch(vlan-config)# vtp serverSwitch(vlan-config)#Related Commands
show vtp
vtp (global configuration mode)vtp transparent
To place a device in VTP transparent mode, use the vtp transparent command. To return to VTP server mode, use the no form of this command.
vtp transparent
no vtp transparent
Syntax Description
This command has no arguments or keywords.
Defaults
VTP transparent mode is disabled.
Command Modes
VLAN configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
The vtp transparent command disables VTP from the domain but does not remove the domain from the switch.
If the receiving switch is in transparent mode, the configuration is not changed. Switches in transparent mode do not participate in VTP. If you make VTP or VLAN configuration changes on a switch in transparent mode, the changes are not propagated to the other switches in the network.
The vtp server command is similar to the no vtp transparent command except that it does not return an error if the device is not in transparent mode.
Examples
This example shows how to place the device in VTP transparent mode:
Switch(vlan-config)# vtp transparentSwitch(vlan-config)#This example shows how to return the device to VTP server mode:
Switch(vlan-config)# no vtp transparentSwitch(vlan-config)#Related Commands
show vtp
vtp (global configuration mode)vtp v2-mode
To enable version 2 mode, use the vtp v2-mode command. To disable version 2 mode, use the no form of this command.
vtp v2-mode
no vtp v2-mode
Syntax Description
This command has no arguments or keywords.
Defaults
Version 2 mode is enabled.
Command Modes
VLAN configuration
Command History
12.1(8a)EW
Support for this command was introduced on the Catalyst 4500 series switch.
Usage Guidelines
All switches in a VTP domain must run the same version of VTP. VTP version 1 and VTP version 2 do not operate on switches in the same VTP domain.
If all switches in a domain are VTP version 2-capable, you only need to enable VTP version 2 on one switch; the version number is then propagated to the other version 2-capable switches in the VTP domain.
If you toggle the version 2 mode, parameters of certain default VLANs will be modified.
Examples
This example shows how to enable version 2 mode in the VLAN database:
Switch(vlan-config)# vtp v2-modeSwitch(vlan-config)#This example shows how to disable version 2 mode in the VLAN database:
Switch(vlan-config)# no vtp v2-modeSwitch(vlan-config)#Related Commands
