Table Of Contents

set port flowcontrol

set vlan mapping

set vlan

show mac-address-table aging-time

show mac-address-table dynamic

show mac-address-table static

show mac-address-table

show mls masks

show mls qos interface

show mls qos maps

show mls rp interface

show mls rp ip multicast

show mls rp ipx

show mls rp vtp-domain

show mls rp

show port flowcontrol

show spanning-tree

show spantree

show vlans dot1q

show vlans

show vlan-switch

show vtp

spanning-tree backbonefast

spanning-tree cost

spanning-tree port-priority

spanning-tree vlan

set port flowcontrol

To set the receive flow-control value for a particular Gigabit Ethernet switching module port, use the set port flowcontrol command in privileged EXEC mode. To reset the receive flow-control value to the default, use the no form of this command.

set port flowcontrol {receive | send} [module-number | port-number] {off | on | desired}

no set port flowcontrol {receive | send} [module-number | port-number] {off | on | desired}

Syntax Description

receive	Indicates whether the port can receive administrative status from a remote device.
send	Indicates whether the local port can send administrative status to a remote device.
module-number	(Optional) Number of the module.
port-number	(Optional) Number of the port on the module.
off	When used with receive, it turns off an attached device's ability to send flow-control packets to a local port. When used with send, it turns off the local port's ability to send administrative status to a remote device.
on	When used with receive, it requires that a local port receive administrative status from a remote device. When used with send, the local port sends administrative status to a remote device.
desired	When used with receive, it allows a local port to operate with an attached device that is required to send flow-control packets or with an attached device that is not required to, but may send flow-control packets. When used with send, the local port sends administrative status to a remote device if the remote device supports it.

Defaults

receive—off
send—desired

Default on multiplexed ports is on. The exception to these defaults applies to the 18-port Gigabit Ethernet switching module. For this module, the defaults are shown below:

•Ports 1-2—send is off and receive is desired

•Ports 3-18—send is on and receive is desired

Command Modes

Privileged EXEC

Command History

Release	Modification
12.2(11)T	This command was introduced and implemented on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers

Usage Guidelines

This command is supported on Gigabit Ethernet switching modules only.

Examples

The following examples show how to use the set port flowcontrol command set.

The following example show how to set the port 5/1 flow-control receive administration status to on (port requires far end to send flowcontrol packets):

Router# set port flowcontrol receive 5/1 on

The following example show how to set the port 5/1 flow-control receive administration status to desired (port allows far end to send flowcontrol packets if far end supports it):

Router# set port flowcontrol receive 5/1 desired

The following example show how to set the port 5/1 flow-control receive administration status to off (port does not allow far end to send flowcontrol packets):

Router# set port flowcontrol receive 5/1 off

The following example show how to set port 5/1 flow-control send administration status o on (port sends flowcontrol packets to far end):

Router# set port flowcontrol send 5/1 on

The following example show how to set port 5/1 flow-control send administration status to desired (port sends flowcontrol packets to far end if far end supports it):

Router# set port flowcontrol send 5/1 desired

The following example show how to set port 5/1 flow-control send administration status to off (port does not send flowcontrol packets to far end):

Router# set port flowcontrol send 5/1 off

Related Commands

Command	Description
show port flowcontrol	Displays per-port status information and statistics related to flow control.

set vlan mapping

To map 802.1Q virtual LANs (VLANs) to Inter-Switch Link (ISL) VLANs, use the set vlan mapping command in privileged EXEC mode.

set vlan mapping dot1q 1q-vlan-number isl isl-vlan-number

Syntax Description

dot1q	Specifies the 802.1Q VLAN.
1q-vlan-number	Number identifying the 802.1Q VLAN; valid values are 1001 to 4095.
isl	Specifies the ISL VLAN.
isl-vlan-number	Number identifying the ISL VLAN; valid values are 1 to 1000.

Defaults

No 802.1Q-to-ISL mappings are defined.

Command Modes

Privileged EXEC

Usage Guidelines

IEEE 802.1Q VLAN trunks support VLANs 1 through 4095. ISL VLAN trunks support VLANs 1 through 1000. The switch automatically maps 802.1Q VLANs 1000 and lower to ISL VLANs with the same number.

The native VLAN of the 802.1Q trunk cannot be used in the mapping.

Use this feature to map 802.1Q VLANs above 1000 to ISL VLANs. Note that if you map a 802.1Q VLAN over 1000 to an ISL VLAN, the corresponding 802.1Q VLAN will be blocked. For example, if you map 802.1Q VLAN 2000 to ISL VLAN 200, then 802.1Q VLAN 200 will be blocked.

You can map up to seven VLANs. Only one 802.1Q VLAN can be mapped to an ISL VLAN. For example, if 802.1Q VLAN 800 has been automatically mapped to ISL VLAN 800, do not manually map any other 802.1Q VLANs to ISL VLAN 800.

You cannot overwrite existing 802.1Q VLAN mapping. If the 802.1Q VLAN number is in the mapping table, the command is aborted. You must first clear that mapping.

If vlan-number does not exist, then either of the following occurs:

•If the switch is in server or transparent mode, the VLAN is created with all default values.

•If the switch is in client mode, then the command proceeds without creating the VLAN. A warning will be given indicating that the VLAN does not exist.

If the table is full, the command is aborted with an error message indicating the table is full.

Examples

The following example shows how to map VLAN 1022 to ISL VLAN 850:

Router# set vlan mapping dot1q 1022 isl 850

Vlan 850 configuration successful

Vlan mapping successful

The following example shows the display if you enter a VLAN that does not exist:

Router# set vlan mapping dot1q 1017 isl 999

Vlan mapping successful

Warning: vlan 999 non-existent

Vlan 999 configuration successful

The following example shows the display if you enter an existing mapping:

Router# set vlan mapping dot1q 1033 isl 722

722 exists in the mapping table. Please clear the mapping first.

The following example shows the display if the mapping table is full:

Router# set vlan mapping dot1q 1099 isl 917

Vlan Mapping Table Full.

Related Commands

Command	Description
clear vlan mapping	Deletes existing 802.1Q VLAN to ISL VLAN-mapped pairs.
show vlans	Displays VLAN subinterfaces.

set vlan

To group ports into a virtual LAN (VLAN), use the set vlan command in privileged EXEC mode.

set vlan vlan-number module/port

set vlan vlan-number [name name] [type {ethernet | fddi | fddinet | trcrf | trbrf}]
[state {active | suspend}] [sa-id sa-id] [mtu mtu] [ring hex-ring-number]
[decring decimal-ring-number] [bridge bridge-number] [parent vlan-number] [mode {srt |
srb}] [stp {ieee | ibm | auto}] [translation vlan-number] [backupcrf {off | on}]
[aremaxhop hop-count] [stemaxhop hop-count]

Syntax Description

vlan-number	Number identifying the VLAN.
module	Number of the module. This argument is not valid when defining or configuring Token Ring Bridge Relay Functions (TRBRFs).
port	Number of the port on the module belonging to the VLAN; this argument does not apply to TRBRFs.
name name	(Optional) Defines a text string used as the name of the VLAN (1 to 32 characters).
type {ethernet | fddi | fddinet | trcrf | trbrf}	(Optional) Identifies the VLAN type. The default type is Ethernet.
state {active | suspend}	(Optional) Specifies whether the state of the VLAN is active or suspended. VLANs in suspended state do not pass packets. The default state is active.
sa-id sa-id	(Optional) Specifies the security association identifier. Possible values are 1 to 4294967294. The default is 100001 for VLAN1, 100002 for VLAN 2, 100003 for VLAN 3, and so on. This argument does not apply to Token Ring Concentrator Relay Functions (TRCRFs) or TRBRFs.
mtu mtu	(Optional) Specifies the maximum transmission unit (packet size, in bytes) that the VLAN can use. Possible values are 576 to 18190. The default is 1500 bytes.
ring hex-ring-number	(Optional) Specifies the logical ring number for Token Ring VLANs. Possible values are hexadecimal numbers 0x1 to 0xFFF. This argument is valid and required only when defining a TRCRF.
decring decimal-ring-number	(Optional) Specifies the logical ring number for Token Ring VLANs. Possible values are decimal numbers 1 to 4095. This argument is valid and required only when defining a TRCRF.
bridge bridge-number	(Optional) Specifies the identification number of the bridge. Possible values are hexadecimal numbers 0x1 to 0xF. For Token Ring VLANs, the default is 0F. This argument is not valid for TRCRFs.
parent vlan-number	(Optional) Sets a parent VLAN. The range for vlan-number is 2 to 1005. This argument identifies the TRBRF to which a TRCRF belongs and is required when defining a TRCRF.
mode {srt | srb}	(Optional) Specifies the TRCRF bridging mode.
stp {ieee | ibm | auto}	(Optional) Specifies the Spanning Tree Protocol version for a TRBRF to use: source-routing transparent (ieee), source-route bridging (ibm), or automatic source selection (auto).
translation vlan-number	(Optional) Specifies a translational VLAN used to translate FDDI to Ethernet. Valid values are from 1 to 1005. This argument is not valid for defining or configuring Token Ring VLANs.
backupcrf {off | on}	(Optional) Specifies whether the TRCRF is a backup path for traffic.
aremaxhop hop-count	(Optional) Specifies the maximum number of hops for All-Routes Explorer frames. Possible values are 1 to 14. The default is 7. This argument is only valid when defining or configuring TRCRFs.
stemaxhop hop-count	(Optional) Specifies the maximum number of hops for Spanning-Tree Explorer frames. Possible values are 1 to 14. The default is 7. This argument is only valid when defining or configuring TRCRFs.

Defaults

The default configuration has all switched Ethernet ports and Ethernet repeater ports in VLAN 1. The default SAID is 100001 for VLAN 1, 100002 for VLAN 2, 100003 for VLAN 3, and so on. The default type is Ethernet. The default MTU is 1500 bytes. The default state is active.

The default TRBRF is 1005, the default TRCRF is 1003, and the default MTU for TRBRFs and TRCRFs is 4472. The default state is active. The default aremaxhop is 7; the default stemaxhop is 7.

Command Modes

Privileged EXEC

Usage Guidelines

You cannot use the set vlan command until the networking device is either in VTP transparent mode (set vtp mode) or until a VTP domain name has been set (set vtp).

Valid MTU values for Token Ring VLAN are 1500 or 4472. While you can enter any value for the MTU value, the value you enter defaults to the next lowest valid value.

You cannot set multiple VLANs for Inter-Switch Link (ISL) ports using this command. The VLAN name can be from 1 to 32 characters in length. If adding a new VLAN, the VLAN number must be within the range 2 to 1001. When modifying a VLAN, the valid range for the VLAN number is 2 to 1005.

On a new Token Ring VLAN, if you do not specify the parent parameter for a TRCRF, the default TRBRF (1005) is used.

Examples

The following example shows how to set VLAN 850 to include ports 4 through 7 on module 3. Because ports 4 through 7 were originally assigned to TRCRF 1003, the message reflects the modification of VLAN 1003.

Router# set vlan 850 3/4-7

VLAN 850 modified.

VLAN 1003 modified.

VLAN  Mod/Ports

---- -----------------------

850   3/4-7

Related Commands

Command	Description
clear vlan	Deletes an existing VLAN from a management domain.
show vlans	Displays VLAN subinterfaces.

show mac-address-table aging-time

To display the MAC address aging time, use the show mac-address-table aging-time command in privileged EXEC mode.

Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers

show mac-address-table aging-time

Catalyst Switches

show mac-address-table aging-time [vlan vlan] [[begin | exclude | include] expression]

Syntax Description

Vlan vlan	(Optional) Specifies a VLAN; valid values are from 1 to 1005.
begin	(Optional) Specifies that the output display begin with the line that matches the expression.
exclude	(Optional) Specifies that the output display excludes lines that match the expression.
include	(Optional) Specifies that the output display includes lines that match the specified expression.
expression	Expression in the output to use as a reference point.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.0(7)XE	This command was introduced on Catalyst 6000 family switches.
12.2(2)XT	This command was implemented on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(8)T	This command was integrated into Cisco IOS Release 12.2(8)T on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(11)T	This command was integrated into Cisco IOS Release 12.2(11)T.

Examples

The following example shows how to display the current configured aging time for all VLANs:

Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers

Router# show mac-address-table aging-time 

Mac address aging time 300

Catalyst Switches

Router# show mac-address-table aging-time

Vlan    Aging Time

----    ----------

100     300

200     1000

The following example show how to display the current configured aging time for a specific VLAN:

Router# show mac-address-table aging-time vlan 100

Vlan    Aging Time

----    ----------

 100    300

Related Commands

Command	Description
show mac-address-table address	Displays MAC address table information for a specific MAC address.
show mac-address-table count	Displays the number of entries currently in the MAC address table.
show mac-address-table detail	Displays detailed MAC address table information.
show mac-address-table dynamic	Displays dynamic MAC address table entries only.
show mac-address-table interface	Displays the MAC address table information for a specific interface.
show mac-address-table multicast	Displays multicast MAC address table information.
show mac-address-table protocol	Displays MAC address table information based on protocol.
show mac-address-table static	Displays static MAC address table entries only.
show mac-address-table vlan	Displays the MAC address table information for a specific VLAN.

show mac-address-table dynamic

To display dynamic MAC address table entries only, use the show mac-address-table dynamic command in privileged EXEC mode.

Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers

show mac-address-table dynamic [address mac-address | interface type slot/port | vlan vlan]

Catalyst Switches

show mac-address-table dynamic [address mac-address | detail | interface type number | protocol protocol | vlan vlan] [[begin |exclude | include] expression]

Syntax Description

address mac-address	(Optional) Specifies a 48-bit MAC address; valid format is H.H.H.
detail	(Optional) Specifies a detailed display of MAC address table information.
interface type number	(Optional) Specifies an interface to match; valid type values are FastEthernet and GigabitEthernet, valid number values are from 1 to 9.
interface type	(Optional) Specifies an interface to match; valid type values are FastEthernet and GigabitEthernet.
slot	(Optional) Adds dynamic addresses to module in slot 1 or 2.
port	(Optional) Port interface number ranges based on type of Ethernet switch network module used: 0 to 15 for NM-16ESW 0 to 35 for NM-36ESW 0 to 1 for GigabitEthernet
protocol protocol	(Optional) Specifies a protocol. See the "Usage Guidelines" section for keyword definitions.
vlan vlan	(Optional) Displays entries for a specific VLAN; valid values are from 1 to 1005.
begin	(Optional) Specifies that the output display begin with the line that matches the expression.
exclude	(Optional) Specifies that the output display exclude lines that match the expression.
include	(Optional) Specifies that the output display include lines that match the specified expression.
expression	Expression in the output to use as a reference point.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.0(7)XE	This command was introduced on Catalyst 6000 family switches.
12.2(2)XT	This command was implemented on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(8)T	This command was integrated into Cisco IOS Release 12.2(8)T on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(11)T	This command was integrated into Cisco IOS Release 12.2(11)T.

Usage Guidelines

Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers

The show mac-address-table dynamic command output for an EtherChannel interface changes the port-number designation (for example, 5/7) to a port-group number.

Catalyst Switches

The keyword definitions for the protocol argument are:

•ip—Specifies IP protocol

•ipx—Specifies IPX protocols

•assigned—Specifies assigned protocol entries

•other—Specifies other protocol entries

The show mac-address-table dynamic command output for an EtherChannel interface changes the port-number designation (for example, 5/7) to a port-group number.

Examples

The following examples shows how to display all dynamic MAC address entries:

Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series Routers

Router# show mac-address-table dynamic 

Non-static Address Table:

Destination Address  Address Type  VLAN  Destination Port

-------------------  ------------  ----  --------------------

000a.000a.000a          Dynamic       1     FastEthernet4/0

002a.2021.4567          Dynamic       2     FastEthernet4/0

Catalyst Switches

Router# show mac-address-table dynamic

vlan   mac address     type    protocol  qos             ports

-----+---------------+--------+---------+---+--------------------------------

 200  0010.0d40.37ff  dynamic        ip  --  5/8

   1  0060.704c.73ff  dynamic        ip  --  5/9

4095  0000.0000.0000  dynamic        ip  --  15/1

   1  0060.704c.73fb  dynamic     other  --  5/9

   1  0080.1c93.8040  dynamic        ip  --  5/9

4092  0050.f0ac.3058  dynamic        ip  --  15/1

   1  00e0.4fac.b3ff  dynamic     other  --  5/9

The following example show how to display dynamic MAC address entries with a specific protocol type (in this case, assigned):

Router# show mac-address-table dynamic protocol assigned

vlan   mac address     type    protocol  qos             ports

-----+---------------+--------+---------+---+--------------------------------

4092  0000.0000.0000  dynamic  assigned  --  Router

4092  0050.f0ac.3059  dynamic  assigned  --  Router

   1  0010.7b3b.0978  dynamic  assigned  --  Fa5/9

Router#

The following example shows the detailed output for the previous example:

Router# show mac-address-table dynamic protocol assigned detail

MAC Table shown in details

======================================== 

 Type   Always Learn Trap Modified Notify Capture Protocol Flood

-------+------------+----+--------+------+-------+--------+-----+

     QoS bit      L3 Spare   Mac Address  Age Byte Pvlan Xtag SWbits Index

-----------------+--------+--------------+--------+-----+----+------+-----

DYNAMIC     NO        NO     YES     NO     NO    assigned   NO

   Bit Not On        0     0000.0000.0000  255      4092   0     0     0x3

DYNAMIC     NO        NO     YES     NO     NO    assigned   NO

   Bit Not On        0     0050.f0ac.3059  254      4092   0     0     0x3

DYNAMIC     NO        NO     YES     NO     NO    assigned   NO

   Bit Not On        0     0010.7b3b.0978  254      1      0     0     0x108

Router#

Related Commands

Command	Description
show mac-address-table address	Displays MAC address table information for a specific MAC address.
show mac-address-table aging-time	Displays the MAC address aging time.
show mac-address-table count	Displays the number of entries currently in the MAC address table.
show mac-address-table detail	Displays detailed MAC address table information.
show mac-address-table interface	Displays the MAC address table information for a specific interface.
show mac-address-table multicast	Displays multicast MAC address table information.
show mac-address-table protocol	Displays MAC address table information based on protocol.
show mac-address-table static	Displays static MAC address table entries only.
show mac-address-table vlan	Displays the MAC address table information for a specific VLAN.

show mac-address-table static

To display static MAC address table entries only, use the show mac-address-table static command in privileged EXEC mode.

Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers

show mac-address-table static [address mac-address | interface type slot/port | vlan vlan]

Catalyst Switches

show mac-address-table static [address mac-address | detail | interface type number | protocol protocol | vlan vlan] [[begin |exclude | include] expression]

Syntax Description

address mac-address	(Optional) Specifies a 48-bit MAC address to match; valid format is H.H.H.
detail	(Optional) Specifies a detailed display of MAC address table information.
interface type number	(Optional) Specifies an interface to match; valid type values are Ethernet, FastEthernet, and Gigabit Ethernet and valid number values are from 1 to 9.
interface type	(Optional) Specifies an interface to match; valid type values are FastEthernet and Gigabit Ethernet.
slot	(Optional) Adds dynamic addresses to module in slot 1 or 2.
port	(Optional) Port interface number ranges based on type of Ethernet switch network module used: 0 to 15 for NM-16ESW 0 to 35 for NM-36ESW 0 to 1 for Gigabit Ethernet
protocol protocol	(Optional) Specifies a protocol. See the "Usage Guidelines" section for keyword definitions.
vlan vlan	(Optional) Displays entries for a specific VLAN; valid values are from 1 to 1005.
begin	(Optional) Specifies that the output display begin with the line that matches the expression.
exclude	(Optional) Specifies that the output display exclude lines that match the expression.
include	(Optional) Specifies that the output display include lines that match the specified expression.
expression	Expression in the output to use as a reference point.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.0(7)XE	This command was introduced on Catalyst 6000 family switches.
12.2(2)XT	This command was implemented on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(8)T	This command was integrated into Cisco IOS Release 12.2(8)T on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(11)T	This command was integrated into Cisco IOS  Release 12.2(11)T.

Usage Guidelines

Catalyst Switches

The keyword definitions for the protocol argument are:

•ip—Specifies IP protocol.

•ipx—Specifies IPX protocols.

•assigned—Specifies assigned protocol entries.

•other—Specifies other protocol entries.

Examples

The following example shows how to display all static MAC address entries:

Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers

Router# show mac-address-table static 

Static Address Table:

Destination Address  Address Type  VLAN  Destination Port

-------------------  ------------  ----  --------------------

2323.3214.5432          Static        4     FastEthernet4/1

2323.3214.5431          Static        5     FastEthernet4/1

2323.3214.5432          Static        6     FastEthernet4/1

2323.3214.5434          Static        7     FastEthernet4/1

2323.3214.5435          Static        8     FastEthernet4/1

Catalyst Switches

Router# show mac-address-table static

*Oct 22 12:15:35: %SYS-5-CONFIG_I: Configured from console by console 

vlan   mac address     type    protocol  qos             ports

-----+---------------+--------+---------+---+--------------------------------

 200  0050.3e8d.6400  static   assigned  --  Router

 100  0050.3e8d.6400  static   assigned  --  Router

4092  0050.f0ac.3058  static      other  --  Router

 917  0100.0cdd.dddd  static      other  --  Fa5/9,Router,Switch

   5  0050.3e8d.6400  static   assigned  --  Router

 303  0100.0cdd.dddd  static      other  --  Fa5/9,Router,Switch

 850  0100.0cdd.dddd  static      other  --  Fa5/9,Router,Switch

1002  0100.0cdd.dddd  static      other  --  Fa5/9,Router,Switch

 802  0100.0cdd.dddd  static      other  --  Fa5/9,Router,Switch

   2  0100.0cdd.dddd  static      other  --  Fa5/9,Router,Switch

 304  0100.5e00.0001  static         ip  --  Fa5/9,Switch

.

.

.

The following example shows how to display static MAC address entries with a specific protocol type (in this case, assigned):

Router# show mac-address-table static protocol assigned

vlan   mac address     type    protocol  qos             ports

-----+---------------+--------+---------+---+--------------------------------

 200  0050.3e8d.6400  static   assigned  --  Router

 100  0050.3e8d.6400  static   assigned  --  Router

   5  0050.3e8d.6400  static   assigned  --  Router

The following example shows the detailed output for the previous example:

Router# show mac-address-table static protocol assigned detail

       MAC Table shown in details

======================================== 

 Type   Always Learn Trap Modified Notify Capture Protocol Flood

-------+------------+----+--------+------+-------+--------+-----+

     QoS bit      L3 Spare   Mac Address  Age Byte Pvlan Xtag SWbits Index

-----------------+--------+--------------+--------+-----+----+------+-----

STATIC      NO        NO     NO      NO     NO    assigned   NO

   Bit Not On        0     0050.3e8d.6400  254      200    1     0     0x3

STATIC      NO        NO     NO      NO     NO    assigned   NO

   Bit Not On        0     0050.3e8d.6400  254      100    1     0     0x3

STATIC      NO        NO     NO      NO     NO    assigned   NO

   Bit Not On        0     0050.3e8d.6400  254      5      1     0     0x3

S   Bit Not On        0     0050.f0ac.3058  254      4092   1     0     0x3   

.

.

.

Related Commands

Command	Description
show mac-address-table address	Displays MAC address table information for a specific MAC address.
show mac-address-table aging-time	Displays the MAC address aging time.
show mac-address-table count	Displays the number of entries currently in the MAC address table.
show mac-address-table detail	Displays detailed MAC address table information.
show mac-address-table dynamic	Displays dynamic MAC address table entries only.
show mac-address-table interface	Displays the MAC address table information for a specific interface.
show mac-address-table multicast	Displays multicast MAC address table information.
show mac-address-table protocol	Displays MAC address table information based on protocol.
show mac-address-table vlan	Displays the MAC address table information for a specific VLAN.

show mac-address-table

To display the MAC address table, use the show mac-address-table command in privileged EXEC mode.

Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers

show mac-address-table [static | dynamic | secure | self | aging-time | count] [address hardware-address] [interface type] [fa | gi slot/port] [vlan vlan-id]

Catalyst Switches

show mac-address-table [static | dynamic | secure | self | aging-time | count] [address hardware-address] [interface interface] [atm slot/port] [vlan vlan-id]

Syntax Description

static	(Optional) Displays only the static addresses.
dynamic	(Optional) Displays only the dynamic addresses.
secure	(Optional) Displays only the secure addresses.
self	(Optional) Displays only addresses added by the switch itself.
aging-time	(Optional) Displays aging-time for dynamic addresses for all VLANs.
count	(Optional) Displays a count for different kinds of MAC addresses.
address hardware-address	(Optional) Displays information for a specific hardware address.
interface type	(Optional) Displays addresses for a specific port.
interface interface	(Optional) Displays addresses for a specific port.
fa	(Optional) Specifies FastEthernet.
gi	(Optional) Specifies GigabitEthernet.
slot/port	(Optional) Adds dynamic addresses to module in slot 1 or 2.
atm slot/port	(Optional) Adds dynamic addresses to ATM module slot/port. Use 1 or 2 for the slot number. Use 0 as the port number.
vlan vlan-id	(Optional) Displays addresses for a specific VLAN. Valid IDs are from 1 to 1005; do not enter leading zeroes.

Command Modes

Privileged EXEC

Command History

Release	Modification
11.2(8)SA	This command was first introduced.
11.2(8)SA3	The self, aging-time, count, and vlan vlan-id keywords were added.
11.2(8)SA5	The atm slot/port keywords were added.
12.2(2)XT	This command was implemented on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(8)T	This command was integrated into Cisco IOS Release 12.2(8)T on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(11)T	This command was integrated into Cisco IOS Release 12.2(11)T.

Usage Guidelines

This command displays the MAC address table for the switch. Specific views can be defined by using the optional keywords and values. If more than one optional keyword is used, then all of the conditions must be true in order for that entry to be displayed.

Examples

Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers

The following is sample output from the show mac-address-table command:

Router# show mac-address-table

Dynamic Addresses Count:               9

Secure Addresses (User-defined) Count: 0

Static Addresses (User-defined) Count: 0

System Self Addresses Count:           41

Total MAC addresses:                   50

Non-static Address Table:

Destination Address  Address Type  VLAN  Destination Port

-------------------  ------------  ----  --------------------

0010.0de0.e289       Dynamic          1  FastEthernet0/1

0010.7b00.1540       Dynamic          2  FastEthernet0/5

0010.7b00.1545       Dynamic          2  FastEthernet0/5

0060.5cf4.0076       Dynamic          1  FastEthernet0/1

0060.5cf4.0077       Dynamic          1  FastEthernet0/1

0060.5cf4.1315       Dynamic          1  FastEthernet0/1

0060.70cb.f301       Dynamic          1  FastEthernet0/1

00e0.1e42.9978       Dynamic          1  FastEthernet0/1

00e0.1e9f.3900       Dynamic          1  FastEthernet0/1 

Catalyst Switches

The following is sample output from the show mac-address-table command:

Switch# show mac-address-table

Dynamic Addresses Count:               9

Secure Addresses (User-defined) Count: 0

Static Addresses (User-defined) Count: 0

System Self Addresses Count:           41

Total MAC addresses:                   50

Non-static Address Table:

Destination Address  Address Type  VLAN  Destination Port

-------------------  ------------  ----  --------------------

0010.0de0.e289       Dynamic          1  FastEthernet0/1

0010.7b00.1540       Dynamic          2  FastEthernet0/5

0010.7b00.1545       Dynamic          2  FastEthernet0/5

0060.5cf4.0076       Dynamic          1  FastEthernet0/1

0060.5cf4.0077       Dynamic          1  FastEthernet0/1

0060.5cf4.1315       Dynamic          1  FastEthernet0/1

0060.70cb.f301       Dynamic          1  FastEthernet0/1

00e0.1e42.9978       Dynamic          1  FastEthernet0/1

00e0.1e9f.3900       Dynamic          1  FastEthernet0/1 

Related Commands

Command	Description
clear mac-address-table	Deletes entries from the MAC address table.

show mls masks

To display the details of the Access Control Parameters (ACPs) that are used for Multilayer Switching (MLS) quality of service (QoS) and security access control lists (ACLs), use the show mls masks command in privileged EXEC mode.

show mls masks [qos | security]

Syntax Description

qos	(Optional) Displays details of ACPs used for QoS ACLs.
security	(Optional) Displays details of ACPs used for security ACLs.

---

Note ACPs are called masks in the command-line interface (CLI) commands and output.

---

Command Modes

Privileged EXEC

Command History

Release	Modification
12.1(6)EA2	This command was introduced.
12.2(15)ZJ	This command was implemented on the following platforms: Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.3(4)T	This command was integrated into Cisco IOS Release 12.3(4)T on the following platforms: Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.

Usage Guidelines

Use the show mls mask command without keywords to display all ACPs configured on the switch.

Use this command with the qos keyword to display the ACPs used for QoS ACLs.

Use this command with the security keyword to display the ACPs used for security ACLs.

---

Note You can configure up to four ACPs (QoS and security) on a switch.

---

Examples

The following is sample output from the show mls masks command. In this example, Mask 1 is a QoS ACP consisting of an IP source address (with wildcard bits 0.0.0.255), an IP destination address, and Layer 4 destination port fields. This ACP is used by the QoS policy maps pmap1 and pmap2.

Router# show mls masks

Mask1

        Type : qos

        Fields : ip-sa(0.0.0.255), ip-da(host), dest-port

        Policymap: pmap1

            Interfaces: Fa0/9, Gi0/1

        Policymap: pmap2

            Interfaces: Fa0/1, Fa0/5, Fa0/13

Related Commands

Command	Description
ip access-group	Applies an IP ACL to an interface.
policy-map	Creates or modifies a policy map that can be attached to one or more interfaces to specify a service policy.

show mls qos interface

To display Multilayer Switching (MLS) quality of service (QoS) information at the interface level, use the show mls qos interface command in privileged EXEC mode.

show mls qos interface [interface-id] [policers]

Syntax Description

interface-id	(Optional) Specifies the interface for which QoS information is to be displayed.
policers	(Optional) Displays all the policers configured on the interface, their settings, and the number of policers unassigned.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.1(6)EA2	This command was introduced.
12.2(15)ZJ	This command was implemented on the following platforms: Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.3(4)T	This command was integrated into Cisco IOS Release 12.3(4)T on the following platforms: Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.

Usage Guidelines

Use the show mls qos interface command without keywords to display parameters for all interfaces.

Use the show mls qos interface interface-id command to display the parameters for a specific interface.

Examples

The following is sample output from the show mls qos interface fastethernet0/1 command:

Router# show mls qos interface fastethernet0/1

FastEthernet0/1

trust state: trust cos

COS override: dis

default COS: 0

Related Commands

Command	Description
mls qos cos	Defines the default MLS CoS value of a port or assigns the default CoS value to all incoming packets on the port.
mls qos map	Defines the MLS CoS-to-DSCP map and DSCP-to-CoS map.
mls qos trust	Configures the MLS port trust state and classifies traffic by an examination of the CoS or DSCP value.

show mls qos maps

To display Multilayer Switching (MLS) quality of service (QoS) mapping information, use the show mls qos maps command in privileged EXEC mode.

show mls qos maps [cos-dscp | dscp-cos]

Syntax Description

cos-dscp	(Optional) Displays the class of service (CoS)-to-Differentiated Services Code Point (DSCP) map.
dscp-cos	(Optional) Displays the DSCP-to-CoS map.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.1(6)EA2	This command was introduced.
12.2(15)ZJ	This command was implemented on the following platforms: Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.3(4)T	This command was integrated into Cisco IOS Release 12.3(4)T on the following platforms: Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.

Usage Guidelines

Maps are used to generate an internal DSCP value, which represents the priority of the traffic. Use the show mls qos maps command without keywords to display all maps.

Use this command with the cos-dscp keyword to display the CoS-to-DSCP map.

Use this command with the dscp-cos keyword to display the DSCP-to-CoS map.

Examples

The following is sample output from the show mls qos maps cos-dscp command:

Router# show mls qos maps cos-dscp

Cos-dscp map:

        cos:  0  1  2  3  4  5  6  7

     --------------------------------

       dscp:  8  8  8  8 24 32 56 56

The following is sample output from the show mls qos maps dscp-cos command:

Router# show mls qos maps dscp-cos

Dscp-cos map:

       dscp:  0  8 10 16 18 24 26 32 34 40 46 48 56

     -----------------------------------------------

        cos:  0  1  1  1  2  2  3  3  4  4  5  6  7

The following is sample output from the show mls qos maps command:

Router# show mls qos maps

Dscp-cos map:

       dscp:  0  8 10 16 18 24 26 32 34 40 46 48 56

     -----------------------------------------------

        cos:  0  1  1  2  2  3  7  4  4  5  5  7  7

   Cos-dscp map:

        cos:  0  1  2  3  4  5  6  7

     --------------------------------

       dscp:  0  8 16 24 32 40 48 56

Related Commands

Command	Description
mls qos map	Defines the CoS-to-DSCP map and DSCP-to-CoS map.

show mls rp interface

To display IPX Multilayer Switching (MLS) details for the Route Processor (RP), including specific information about the Multilayer Switching Protocol (MLSP), use the show mls rp interface command in user EXEC or privileged EXEC mode.

show mls rp interface type number

Syntax Description

type	Interface type.
number	Interface number.

Command Modes

User EXEC
Privileged EXEC

Command History

Release	Modification
12.0(5)T	This command was introduced.

Examples

The following displays sample output from the show mls rp interface command. The interface type is VLAN, and its number is 10.

Router# show mls rp interface vlan 10

IPX MLS active on Vlan 10, domain WBU

Related Commands

Command	Description
mls rp ipx (global)	Enables the router as an IPX MLS RP.
mls rp locate ipx	Displays information about all switches currently shortcutting for the specified IPX flow(s).
mls rp vtp-domain	Assigns an MLS interface to a specific VTP domain on the MLS RP.
mls rp management-interface	Designates an interface as the management interface for MLSP packets.
mls rp vlan-id	Assigns a VLAN identification number to an IPX MLS interface.
show mls rp ipx	Displays details for all IPX MLS interfaces on the IPX MLS router.
show mls rp vtp-domain	Displays IPX MLS interfaces for a specific VTP domain on the route processor.

show mls rp ip multicast

To display hardware-switched multicast flow information about IP multicast Multilayer Switching (MLS), use the show mls rp ip multicast command in user EXEC or privileged EXEC mode.

show mls rp ip multicast [locate] [group [source] [vlan-id]] | [statistics] | [summary]

Syntax Description

locate	(Optional) Displays flow information associated with the switch. This keyword applies only to a single router and multiple switches.
group	(Optional) Address of the IP multicast group about which to display information.
source	(Optional) IP multicast source sending to the specified multicast group about which to display information.
vlan-id	(Optional) Source VLAN about which to display information.
statistics	(Optional) Displays MLS statistics.
summary	(Optional) Displays MLS summary.

Command Modes

User EXEC
Privileged EXEC

Command History

Release	Modification
12.0(5)T	This command was introduced.

Examples

The following is sample output of the show mls rp ip multicast command using the locate keyword:

Router# show mls rp ip multicast locate

Source           Group            Vlan  SwitchIP         SwitchMAC

------           -----            ----  --------         ---------

192.1.10.6       239.255.158.197  10    1.2.10.199       0010.a60b.b4ff

The following is sample output of the show mls rp ip multicast command for a specific IP multicast group:

Router# show mls rp ip multicast 224.1.1.1

Multicast hardware switched flows:

(1.1.13.1, 224.1.1.1) Incoming interface: Vlan13, Packets switched: 61590

Hardware switched outgoing interfaces: Vlan20 Vlan9 

MFD installed: Vlan13 

(1.1.9.3, 224.1.1.1) Incoming interface: Vlan9, Packets switched: 0

Hardware switched outgoing interfaces: Vlan20 

MFD installed: Vlan9 

(1.1.12.1, 224.1.1.1) Incoming interface: Vlan12, Packets switched: 62010

Hardware switched outgoing interfaces: Vlan20 Vlan9 

MFD installed: Vlan12 

(1.1.12.3, 224.1.1.1) Incoming interface: Vlan12, Packets switched: 61980

Hardware switched outgoing interfaces: Vlan20 Vlan9 

MFD installed: Vlan12 

(1.1.11.1, 224.1.1.1) Incoming interface: Vlan11, Packets switched: 62430

Hardware switched outgoing interfaces: Vlan20 Vlan9 

MFD installed: Vlan11 

(1.1.11.3, 224.1.1.1) Incoming interface: Vlan11, Packets switched: 62430

Hardware switched outgoing interfaces: Vlan20 Vlan9 

MFD installed: Vlan11 

Total shortcut installed: 6

The following is sample output of the show mls rp ip multicast command using the statistics keyword:

Router# show mls rp ip multicast statistics

MLS Multicast Operation Status:

MLS Multicast configuration and state:

    Router Mac: 0010.298f.0009

    Switch Mac: 0010.0d70.a3ff      Switch IP: 1.2.10.195

    MLS Multicast Operating state: ACTIVE

    Active management vlan: Vlan1, 192.1.4.1

    User configured management vlan: None, 0.0.0.0

    Include-List: IP1 = 192.1.28.2, IP2 = 0.0.0.0

    Router IP used in MLS Multicast messages: 192.1.28.2

MLS Multicast statistics:

    Keepalive sent: 90

    Keepalive ACK received: 90

    Open request sent: 3

    Open request ACK received: 3

    Delete notifications received: 3

    Flow statistics messages received: 181

    Flow message sent: 14

    Flow message Ack received: 14

    Flow message Nack received: 0

    Flow install Ack: 2

    Flow install Nack: 0

    Flow update Ack: 7

    Flow update Nack: 0

    Flow delete Ack: 0

    Complete flow install Ack: 3

    Complete flow install Nack: 0

    Complete flow delete Ack: 1

    Input vlan delete Ack: 0

    Output vlan delete Ack: 0

    Global delete sent: 1

    L2 entry not found error: 0

    LTL entry not found error: 0

    MET entry not found error: 0

    L3 entry not found error: 0

    L3 entry exists error : 0

    Hash collision error : 0

    Sequence number error : 0

    None-supported error : 0

    Generic error : 0

The following is sample output of the show mls rp ip multicast command using the summary keyword:

Router# show mls rp ip multicast summary

Switch IP:0.0.0.0  Switch MAC:0000.0000.0000

Number of complete flows: 0

Total hardware-switched flows: 0

Switch IP:1.2.10.199  Switch MAC:0010.a60b.b4ff

Number of complete flows: 1

Total hardware-switched flows: 1

Related Commands

Command	Description
mls rp ip multicast	Enables IP multicast MLS (hardware switching) on an external or internal router in conjunction with Layer 3 switching hardware for the Catalyst 5000 switch.

show mls rp ipx

To display details for all IPX Multilayer Switching (MLS) interfaces on the IPX MLS router, use the show mls rp ipx command in privileged EXEC mode.

show mls rp ipx

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.0(5)T	This command was introduced.

Usage Guidelines

This command gives you details about the following:

•MLS status (enabled or disabled) for switch interfaces and subinterfaces

•Flow mask required when creating Layer 3 switching entries for the router

•Current settings for the keepalive timer, retry timer, and retry count

•MLS identifier used in Multilayer Switching Protocol (MLSP) messages

•List of all interfaces in all Virtual Trunk Protocol (VTP) domains enabled for MLS

Examples

The following example displays sample output from the show mls rp ipx command for all IPX MLS interfaces on an MLS-Route Processor (RP):

Router# show mls rp ipx

ipx multilayer switching is globally enabled

ipx mls inbound acl override is globally disabled

mls id is 0050.73ff.b580

mls ip address 5.5.5.155

IPX MLS flow mask is source-destination

number of domains configured for mls 1

vlan domain name:Engineering

   current ipx flow mask:source-destination

   ipx current/next global purge:false/false

   ipx current/next purge count:0/0

   current sequence number:4086390283

   current/maximum retry count:0/10

   current domain state:no-change

   domain uptime:03:13:09

   keepalive timer expires in 3 seconds

   retry timer not running

   change timer not running

   1 management interface(s) currently defined:

      vlan 21 on Vlan21

   2 mac-vlan(s) enabled for ipx multi-layer switching:

      mac 0010.0738.2917

         vlan id(s)

         22   

      mac 0050.73ff.b5b8

         vlan id(s)

         21   

   router currently aware of following 1 switch(es):

      switch id 00e0.fe4a.aeff

Related Commands

Command	Description
mls rp ipx (global)	Enables the router as an IPX MLS RP.
mls rp locate ipx	Displays information about all switches currently shortcutting for the specified IPX flows.
mls rp management-interface	Designates an interface as the management interface for MLSP packets.
mls rp vlan-id	Assigns a VLAN identification number to an IPX MLS interface.
show mls rp interface	Displays IPX MLS details for the RP, including specific information about the MLSP.
show mls rp vtp-domain	Displays IPX MLS interfaces for a specific VTP domain on the RP.

show mls rp vtp-domain

To display IPX Multilayer Switching (MLS) interfaces for a specific Virtual Trunk Protocol (VTP) domain on the Route Processor (RP), use the show mls rp vtp-domain command in privileged EXEC mode.

show mls rp vtp-domain domain-name

Syntax Description

domain-name

The name of the VTP domain whose MLS interfaces will be displayed.

Command Modes

Privileged EXEC

Command History

Release	Modification
11.3(3) WA4(4)	This command was introduced.

Examples

This example shows details about IPX MLS interfaces in a VTP domain named WBU:

Router# show mls rp vtp-domain WBU

vlan domain name: WBU

current ipx flow mask: destination

   ipx current/next global purge: false/false

   ipx current/next purge count: 0/0

   current ipx flow mask: destination

   ipx current/next global purge: false/false

   ipx current/next purge count: 0/0

   current sequence number: 590678296

   current/maximum retry count: 0/10

   current domain state: no-change

   domain uptime: 1d14h

   keepalive timer expires in 3 seconds

   retry timer not running

   change timer not running

   fcp subblock count = 20

   1 management interface(s) currently defined:

      vlan 2 on Vlan2

   20 mac-vlan(s) configured for multi-layer switching

   17 mac-vlan(s) enabled for ipx multi-layer switching:

      mac 0010.0738.2917

         vlan id(s)

         2    3    4    5    6    7    8    9    10   12   13

         14   15   88   99

      mac 0090.6dfc.5800

         vlan id(s)

         20   21

   18 mac-vlan(s) enabled for ipx multi-layer switching:

      mac 0010.0738.2917

         vlan id(s)

         2    3    4    5    6    7    8    9    10   11   12

         13   14   15   66   77   88   99

   router currently aware of following 1 switch(es):

      switch id 0010.141f.6fff

Related Commands

Command	Description
mls rp ipx (global)	Enables the router as an IPX MLS RP.
mls rp locate ipx	Displays information about all switches currently shortcutting for the specified IPX flows.
mls rp management-interface	Designates an interface as the management interface for MLSP packets.
mls rp vlan-id	Assigns a VLAN identification number to an IPX MLS interface.
show mls rp interface	Displays IPX MLS details for the RP, including specific information about the MLSP.
show mls rp ipx	Displays details for all IPX MLS interfaces on the IPX MLS router.
show mls rp vtp-domain	Displays IPX MLS interfaces for a specific VTP domain on the RP.

show mls rp

To display Multilayer Switching (MLS) details, including specifics for the Multilayer Switching Protocol (MLSP), use the show mls rp command in user EXEC or privileged EXEC mode.

show mls rp [interface]

Syntax Description

interface

(Optional) Displays information for one interface. Without this argument, detailed views of all interfaces are displayed.

Command Modes

User EXEC
Privileged EXEC

Command History

Release	Modification
11.3(3) WA4(4)	This command was introduced.

Examples

The following is sample output for the show mls rp command:

Router# show mls rp

multilayer switching is globally enabled

mls id is 00e0.fefc.6000

mls ip address 10.20.26.64

mls flow mask is ip-flow

vlan domain name: WBU

   current flow mask: ip-flow

   current sequence number: 80709115

   current/maximum retry count: 0/10

   current domain state: no-change

   current/next global purge: false/false

   current/next purge count: 0/0

   domain uptime: 13:03:19

   keepalive timer expires in 9 seconds

   retry timer not running

   change timer not running

   fcp subblock count = 7

   1 management interface(s) currently defined:

      vlan 1 on Vlan1

   7 mac-vlan(s) configured for multi-layer switching:

      mac 00e0.fefc.6000

         vlan id(s)

         1    10   91   92   93   95   100

   router currently aware of following 1 switch(es):

      switch id 0010.1192.b5ff

The following is sample output for the show mls rp command for a specific interface:

Router# show mls rp int vlan 10

mls active on Vlan10, domain WBU

Related Commands

Command	Description
mls rp ip	Enables MLSP.
mls rp management-interface	Designates an interface as the management interface for MLSP packets.
mls rp nde-address	Specifies a NetFlow Data Export address.
mls rp vlan-id	Assigns a VLAN ID.
mls rp vtp-domain	Selects the router interface to be Layer 3 switched and then adds that interface to a VTP domain.
show mls rp vtp-domain	Displays MLS interfaces for a specific VTP domain.

show port flowcontrol

To display per-port status information and statistics related to flow control, use the show port flowcontrol command in privileged EXEC mode.

show port flowcontrol [module-number[/port-number]]

Syntax Description

module-number	(Optional) Number of the module.
port-number	(Optional) Number of the port on the module. If you do not specify a number, filters configured on all the ports on the module are shown.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.2(11)T	This command was introduced and implemented on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.

Usage Guidelines

The Catalyst 2948G is a fixed configuration switch. All ports are located on module 2; for this reason, if you enter module-number/port-number 1/N, an error message is displayed.

Examples

The following example shows how to display the flow-control port status and statistics:

Router# show port flowcontrol

Port   Send-Flowcontrol   Receive-Flowcntl   RxPause   TxPause

       Admin   Oper       Admin   Oper

-----  ----------------   ----------------   -------   ------

 3/1   on      disagree   on      disagree   0         0

 3/2 	  off     off        off     off        0         0

 3/3   desired on         desired off        10        10

Table 3 describes the fields shown in the display.

Table 3 show port flowcontrol Field Descriptions 

Field	Description
Port	Module and port number.
Send-Flowcontrol Admin	Flow-control administration. Possible settings: •On indicates the local port sends flow control to the far end. •Off indicates the local port does not send flow control to the far end. •Desired indicates the local end sends flow control to the far end if the far end supports it.
Send-Flowcontrol Oper	Flow-control operation. Possible setting: •Disagree indicates the two ports could not agree on a link protocol. •Off indicates that the local port cannot send flowcontrol to a remote port.
Receive-Flowcntl Admin	Flow-control administration. Possible settings: •On indicates the local port requires the far end to send flow control. •Off indicates the local port does not allow the far end to send flow control. •Desired indicates the local end allows the far end to send flow control.
Receive-Flowcntl Oper	Flow-control operation. Possible setting: •Disagree indicates the two ports could not agree on a link protocol. •Off indicates that the local port cannot receive flowcontrol from a remote port.
RxPause	Number of pause frames received.
TxPause	Number of pause frames transmitted.

Related Commands

Command	Description
set port flowcontrol	Sets the receive flow-control value for a particular Gigabit Ethernet switching module port.

show spanning-tree

To display spanning-tree information for the specified spanning-tree instances, use the show spanning-tree command in privileged EXEC mode.

show spanning-tree [bridge-group] [active | backbonefast | blockedports | bridge | brief | inconsistentports | interface interface-id | pathcost method | root | summary [totals] | uplinkfast | vlan vlan-id]

Syntax Description

bridge-group	(Optional) Specifies the bridge group number. The range is 1 to 255.
active	(Optional) Displays spanning-tree information on active interfaces only.
backbonefast	(Optional) Displays spanning-tree BackboneFast status.
blockedports	(Optional) Displays blocked port information.
bridge	(Optional) Displays status and configuration of this switch.
brief	(Optional) Specifies a brief summary of interface information.
inconsistentports	(Optional) Displays information about inconsistent ports.
interface interface-id	(Optional) Specifies a list of interfaces for which spanning-tree information appears. Enter each interface designator, using a space to separate it from the one before and the one after. Ranges are not supported. Valid interfaces include physical ports and virtual LANs (VLANs).
pathcost method	(Optional) Displays the default path cost method.
root	(Optional) Displays root-switch status and configuration.
summary	(Optional) Specifies a summary of port states.
totals	(Optional) Displays the total lines of the spanning-tree state section.
uplinkfast	(Optional) Displays spanning-tree UplinkFast status.
vlan vlan-id	(Optional) Specifies the VLAN ID. The range is 1 to 1005. If the vlan-id value is omitted, the command applies to the spanning-tree instance for all VLANs.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.0(1)T	This command was introduced.
12.0(5.2)WC(1)	This command was integrated into Cisco IOS Release 12.0(5.2)WC(1).
12.1(6)EA2	This command was integrated into Cisco IOS Release 12.1(6)EA2. The bridge-group argument and the active, backbonefast, blockedports, bridge, inconsistentports, pathcost method, root, total, and uplinkfast keywords were added.
12.2(15)ZJ	The syntax added in Cisco IOS Release 12.1(6)EA2 was implemented on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.3(4)T	The platform support and syntax added in Cisco IOS Release 12.2(15)ZJ was integrated into Cisco IOS Release 12.3(4)T .

Usage Guidelines

The keywords and arguments that are available with the show spanning-tree command will vary depending on the platform you are using and the network modules that are installed and operational.

Examples

The following example shows that bridge group 1 is running the VLAN Bridge Spanning Tree Protocol.

Router# show spanning-tree 1

Bridge group 1 is executing the VLAN Bridge compatible Spanning Tree Protocol

Bridge Identifier has priority 32768, address 0000.0c37.b055

Configured hello time 2, max age 30, forward delay 20

We are the root of the spanning tree

Port Number size is 10 bits

Topology change flag not set, detected flag not set

Times: hold 1, topology change 35, notification 2

      hello 2, max age 30, forward delay 20

Timers: hello 0, topology change 0, notification 0

  bridge aging time 300

Port 8 (Ethernet1) of Bridge group 1 is forwarding

   Port path cost 100, Port priority 128

   Designated root has priority 32768, address 0000.0c37.b055

   Designated bridge has priority 32768, address 0000.0c37.b055

   Designated port is 8, path cost 0

   Timers: message age 0, forward delay 0, hold 0

   BPDU: sent 184, received 0

The following is sample output from the show spanning-tree summary command:

Router# show spanning-tree summary

UplinkFast is disabled

Name                 Blocking Listening Learning Forwarding STP Active

-------------------- -------- --------- -------- ---------- ----------

VLAN1                23       0         0        1          24

-------------------- -------- --------- -------- ---------- ----------

              1 VLAN 23       0         0        1          24

Table 4 describes the significant fields shown in the display.

Table 4 show spanning-tree summary Field Descriptions 

Field	Description
UplinkFast	Indicates whether the spanning-tree UplinkFast feature is enabled or disabled.
Name	Name of VLAN.
Blocking	Number of ports in the VLAN in a blocking state.
Listening	Number of ports in a listening state.
Learning	Number of ports in a learning state.
Forwarding	Number of ports in a forwarding state.
STP Active	Number of ports using the spanning-tree protocol (STP).

The following is sample output from the show spanning-tree brief command:

Router# show spanning-tree brief

VLAN1

  Spanning tree enabled protocol IEEE

  ROOT ID    Priority 32768

             Address 0030.7172.66c4

             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec 

VLAN1

  Spanning tree enabled protocol IEEE

  ROOT ID    Priority 32768

             Address 0030.7172.66c4

Port                           Designated

Name    Port ID Prio Cost Sts  Cost  Bridge ID      Port ID

------- ------- ---- ---- ---  ----  -------------- -------

Fa0/11  128.17  128  100  BLK  38    0404.0400.0001 128.17

Fa0/12  128.18  128  100  BLK  38    0404.0400.0001 128.18

Fa0/13  128.19  128  100  BLK  38    0404.0400.0001 128.19

Fa0/14  128.20  128  100  BLK  38    0404.0400.0001 128.20

Fa0/15  128.21  128  100  BLK  38    0404.0400.0001 128.21

Fa0/16  128.22  128  100  BLK  38    0404.0400.0001 128.22

Fa0/17  128.23  128  100  BLK  38    0404.0400.0001 128.23

Fa0/18  128.24  128  100  BLK  38    0404.0400.0001 128.24

Fa0/19  128.25  128  100  BLK  38    0404.0400.0001 128.25

Fa0/20  128.26  128  100  BLK  38    0404.0400.0001 128.26

Fa0/21  128.27  128  100  BLK  38    0404.0400.0001 128.27

Port                           Designated

Name    Port ID Prio Cost Sts  Cost  Bridge ID      Port ID

------- ------- ---- ---- ---  ----  -------------- -------

Fa0/22  128.28  128  100  BLK  38    0404.0400.0001 128.28

Fa0/23  128.29  128  100  BLK  38    0404.0400.0001 128.29

Fa0/24  128.30  128  100  BLK  38    0404.0400.0001 128.30 Hello Time   2 sec  Max Age 20 
sec  Forward Delay 15 sec 

Table 5 describes the significant fields shown in the display.

Table 5 show spanning-tree brief Field Descriptions 

Field	Description
VLAN	VLAN for which spanning-tree information is shown.
Spanning tree enabled protocol	Type of spanning tree (IEEE, IBM, CISCO).
ROOT ID	Indicates the root bridge.
Priority	Priority indicator.
Address	MAC address of the port.
Hello Time	Amount of time, in seconds, that the bridge sends Bridge Protocol Data Units (BPDUs).
Max Age	Amount of time, in seconds, that a BPDU packet should be considered valid.
Forward Delay	Amount of time, in seconds, that the port spends in listening or learning mode.
Port Name	Interface type and number of the port.
Port ID	Identifier of the named port.
Prio	Priority associated with the port.
Cost	Cost associated with the port.
Sts	Status of the port.
Designated Cost	Designated cost for the path.
Designated Bridge ID	Bridge identifier of the bridge assumed to be the designated bridge for the LAN associated with the port.

The following is sample output from the show spanning-tree vlan 1 command:

Router# show spanning-tree vlan 1

Spanning tree 1 is executing the IEEE compatible Spanning Tree protocol

  Bridge Identifier has priority 32768, address 00e0.1eb2.ddc0

  Configured hello time 2, max age 20, forward delay 15

  Current root has priority 32768, address 0010.0b3f.ac80

  Root port is 5, cost of root path is 10

  Topology change flag not set, detected flag not set, changes 1

  Times:  hold 1, topology change 35, notification 2

          hello 2, max age 20, forward delay 15

  Timers: hello 0, topology change 0, notification 0

Interface Fa0/1  in Spanning tree 1 is down

   Port path cost 100, Port priority 128

   Designated root has priority 32768, address 0010.0b3f.ac80

Designated bridge has priority 32768, address 00e0.1eb2.ddc0

   Designated port is 1, path cost 10

   Timers: message age 0, forward delay 0, hold 0

   BPDU: sent 0, received 0 

   .

   .

Table 6 describes the significant fields shown in the display.

Table 6 show spanning-tree vlan Field Descriptions 

Field	Description
Spanning tree	Type of spanning tree (IEEE, IBM, CISCO).
Bridge Identifier	Part of the bridge identifier and taken as the most significant part for bridge ID comparisons.
address	Bridge MAC address.
Root port	Identifier of the root port.
Topology change	Flags and timers associated with topology changes.

The following is sample output from the show spanning-tree interface fastethernet0/3 command:

Router# show spanning-tree interface fastethernet0/3

Interface Fa0/3 (port 3) in Spanning tree 1 is down

   Port path cost 100, Port priority 128

   Designated root has priority 6000, address 0090.2bba.7a40

   Designated bridge has priority 32768, address 00e0.1e9f.4abf

   Designated port is 3, path cost 410

   Timers: message age 0, forward delay 0, hold 0

   BPDU: sent 0, received 0 

Related Commands

Command	Description
spanning-tree vlan	Enables the Spanning Tree Protocol on a VLAN.

show spantree

To display spanning-tree information for a virtual LAN (VLAN) or port, use the show spantree command in privileged EXEC mode.

show spantree [vlan] [active]

show spantree mod/port

Syntax Description

vlan	(Optional) Number of the VLAN; valid values are from 1 to 1001 and from 1025 to 4094.
active	(Optional) Displays only the active ports.
mod/port	Number of the module and the port on the module. The slash mark is required.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.0(7)XE	This command was introduced on the Catalyst 6000 family switches.
12.2(2)XT	This command was implemented on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(8)T	This command was integrated into Cisco IOS Release 12.2(8)T on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.

Usage Guidelines

If you do not specify the VLAN number, VLAN 1 is displayed.

If you are in Multiple Instances of Spanning Tree (MISTP) mode, instance information is not displayed.

The maximum length of the channel port list can be 47. The space in the Port(s) column might not be enough to display the entire list in one line. If this is the case, the port list is split into multiple lines. For example, in the following display, ports 6/5-8, 6/13, 6/15, 6/17, 6/19 are channeling:

.

.

.

Port(s)                  Vlan Port-State    Cost      Prio Portfast Channel_id

------------------------ ---- ------------- --------- ---- -------- ----------

6/5-8,6/13,6/15,6/17,6/1 1    not-connected 2684354   32   disabled 0 

9

.

.

.

The Link Aggregation Control Protocol (LACP) channel protocol does not support half-duplex links. If a port is in active/passive mode and becomes half duplex, the port is suspended (and a syslog message is generated). The port is shown as "connected" using the show port command and as "not connected" using the show spantree command. This discrepancy is because the port is physically connected but never joined between spanning tree. To get the port to join spanning tree, either set the duplex to full or set the channel mode to off for that port.

Examples

The following example shows how to display the active spanning tree port configuration for VLAN 1 while in Per VLAN Spanning Tree (PVST+ mode):

Router# (enable) show spantree 1 active

VLAN 1

Spanning tree mode          PVST+

Spanning tree type          ieee

Spanning tree enabled

Designated Root             00-60-70-4c-70-00

Designated Root Priority    16384

Designated Root Cost        19

Designated Root Port        2/3

Root Max Age   14 sec   Hello Time 2  sec   Forward Delay 10 sec

Bridge ID MAC ADDR          00-d0-00-4c-18-00

Bridge ID Priority          32768

Bridge Max Age 20 sec   Hello Time 2  sec   Forward Delay 15 sec

Port                     Vlan Port-State    Cost      Prio Portfast Channel_id

------------------------ ---- ------------- --------- ---- -------- ----------

 2/3                     1    forwarding           19   32 disabled 0

 2/12                    1    forwarding           19   32 disabled 0 

The following example shows how to display the active spanning-tree port configuration for VLAN 1 (while in MISTP mode):

Router# (enable) show spantree 1 active

VLAN 1

Spanning tree mode          MISTP

Spanning tree type          ieee

Spanning tree enabled

VLAN mapped to MISTP Instance: 1 

Port                     Vlan Port-State    Cost      Prio Portfast Channel_id

------------------------ ---- ------------- --------- ---- -------- ----------

 2/3                     1    forwarding       200000   32 disabled 0

 2/12                    1    forwarding       200000   32 disabled 0

Table 7 describes the significant fields shown in the displays.

Table 7 show spantree Field Descriptions 

Field	Description
VLAN	VLAN for which the spanning-tree information is shown.
Spanning tree	Status of whether Spanning Tree Protocol is enabled or disabled.
Designated Root	MAC address of the designated spanning-tree root bridge.
Designated Root Priority	Priority of the designated root bridge.
Designated Root Cost	Total path cost to reach the root.
Designated Root Port	Port through which the root bridge can be reached (shown only on nonroot bridges).
Root Max Age	Amount of time a bridge packet data unit (BPDU) packet should be considered valid.
Hello Time	Number of times the root bridge sends BPDUs.
Forward Delay	Amount of time the port spends in listening or learning mode.
Port	Port number.
Vlan	VLAN to which the port belongs.
Port-State	Spanning tree port state (disabled, inactive, not-connected, blocking, listening, learning, forwarding, bridging, or type-pvid-inconsistent).
Cost	Cost associated with the port.
Prio	Priority associated with the port.
Portfast	Status of whether the port is configured to use the PortFast feature.
Channel_id	Channel ID number.

Related Commands

Command	Description
show spantree backbonefast	Displays whether the spanning-tree BackboneFast Convergence feature is enabled.
show spantree blockedports	Displays only the blocked ports on a per-VLAN or per-instance basis.
show spantree portvlancost	Shows the path cost for the VLANs or extended-range VLANs.
show spantree statistics	Shows spanning tree statistical information
show spantree summary	Displays a summary of spanning-tree information.
show spantree uplinkfast	Shows the UplinkFast feature settings.

show vlans dot1q

To display statistics about 802.1q virtual LAN (VLAN) subinterfaces, use the show vlans dot1q command in privileged EXEC mode.

show vlans dot1q [internal | interface-type interface-number.subinterface-number [detail] | outer-id [interface-type interface-number | second-dot1q [inner-id | any]] [detail]]

Syntax Description

internal	(Optional) Displays internal Q-in-Q information. Used for troubleshooting purposes.
interface-type	(Optional) Interface type.
interface-number	(Optional) Interface number.
.subinterface-number	(Optional) Subinterface number in the range 1 to 4294967293. A period (.) must be entered between the interface-number argument and the subinterface-number argument.
detail	(Optional) Displays detailed information.
outer-id	(Optional) Outer VLAN identifier. The allowed range is from 1 to 4095.
second-dot1q	(Optional) Displays inner VLAN subinterface information.
inner-id	(Optional) Inner VLAN identifier. The allowed range is from 1 to 4095.
any	(Optional) Displays information for all of the inner VLAN subinterfaces configured as "any."

Command Modes

Privileged EXEC

Command History

Release	Modification
12.3(7)T	This command was introduced.

Usage Guidelines

If no arguments or keywords are entered, statistics for all of the 802.1q VLAN IDs are displayed.

Examples

The following sample output from the show vlans dot1q command displays the statistics for all of the 802.1q VLAN IDs. Only the outer VLAN IDs are displayed.

Router# show vlans dot1q 

Total statistics for 802.1Q VLAN 1:

   441 packets, 85825 bytes input

   1028 packets, 69082 bytes output

Total statistics for 802.1Q VLAN 101:

   5173 packets, 510384 bytes input

   3042 packets, 369567 bytes output

Total statistics for 802.1Q VLAN 201:

   1012 packets, 119254 bytes input

   1018 packets, 120393 bytes output

Total statistics for 802.1Q VLAN 301:

   3163 packets, 265272 bytes input

   1011 packets, 120750 bytes output

Total statistics for 802.1Q VLAN 401:

   1012 packets, 119254 bytes input

   1010 packets, 119108 bytes output

Table 8 describes the significant fields shown in the display.

Table 8 show vlans dot1q Field Descriptions  

Field	Description
Total statistics for 802.1Q VLAN 1	Statistics are shown for the VLAN ID with the specified outer ID.
packets	Number of packets encapsulated by the 802.1Q-in-Q VLAN.
bytes input	Number of bytes input.
bytes output	Number of bytes output.

The following sample output from the show vlans dot1q command displays the statistics for the 802.1q VLAN subinterface configured on Gigabit Ethernet interface 5/0:

Router# show vlans dot1q GigabitEthernet5/0.1011001

GigabitEthernet5/0.1011001 (101/1001)

   1005 packets, 122556 bytes input

   1023 packets, 125136 bytes output

Table 9 describes the significant fields shown in the display.

Table 9 show vlans dot1q (subinterface) Field Descriptions  

Field	Description
GigabitEthernet5/0.1011001 (101/1001)	Statistics are shown for subinterface Gigabit Ethernet 5/0.1011001 with an outer VLAN ID of 101 and an inner VLAN ID of 1001.
packets	Number of packets encapsulated by the 802.1Q-in-Q VLAN.
bytes input	Number of bytes input.
bytes output	Number of bytes output.

The following sample output from the show vlans dot1q command displays the summary statistics for all of the VLAN subinterfaces under the physical interface Gigabit Ethernet 5/0 that have an outer VLAN ID of 101:

Router# show vlans dot1q 101 GigabitEthernet5/0

Total statistics for 802.1Q VLAN 101 on GigabitEthernet5/0:

   5218 packets, 513444 bytes input

   3042 packets, 369567 bytes output

The following sample output from the show vlans dot1q command displays the individual subinterface statistics and summary statistics for all of the VLAN subinterfaces under the physical interface Gigabit Ethernet 5/0 that have an outer VLAN ID of 101:

Router# show vlans dot1q 101 GigabitEthernet5/0 detail

GigabitEthernet5/0.101 (0)

   3220 packets, 269148 bytes input

   1008 packets, 119622 bytes output

GigabitEthernet5/0.1019999 (101/1-1000,1003-2000)

   0 packets, 0 bytes input

   3 packets, 1143 bytes output

GigabitEthernet5/0.1011001 (101/1001)

   1005 packets, 122556 bytes input

   1023 packets, 125136 bytes output

GigabitEthernet5/0.1011002 (101/1002)

   1005 packets, 122556 bytes input

   1008 packets, 123666 bytes output

Total statistics for 802.1Q VLAN 101 on GigabitEthernet5/0:

   5230 packets, 514260 bytes input

   3042 packets, 369567 bytes output

The following sample output from the show vlans dot1q command displays the statistics for an outer VLAN and inner VLAN ID combination. This is a summary that displays the total for all of the subinterfaces on the router that are configured with the specified IDs.

---

Note When ambiguous subinterfaces are used, the statistics displayed are at subinterface-level granularity, not VLAN-ID granularity. For example, when a range of inner VLAN IDs is assigned to a subinterface, the statistics are reported only at the subinterface level. Statistics are not available for each inner VLAN ID.

---

Router# show vlans dot1q 101 second-dot1q 1001 detail

GigabitEthernet5/0.1011001 (101/1001)

   1005 packets, 122556 bytes input

   1023 packets, 125136 bytes output

Total statistics for Outer/Inner VLAN 101/1001:

   1005 packets, 122556 bytes input

   1023 packets, 125136 bytes output

The following sample output from the show vlans dot1q command displays the statistics for a specific outer VLAN ID of 301 and an inner VLAN ID of any. This is a summary that displays the total for all of the subinterfaces on the router that are configured with the specified IDs.

Router# show vlans dot1q 301 second-dot1q any

GigabitEthernet5/0.301999 (301/any)

   0 packets, 0 bytes input

   3 packets, 1128 bytes output

Total statistics for Outer/Inner VLAN 301/"any":

   0 packets, 0 bytes input

   3 packets, 1128 bytes output

The following sample output from the show vlans dot1q command displays some internal information about the Q-in-Q subsystem and is used for troubleshooting purposes (typically by Cisco engineers):

Router# show vlans dot1q internal

Internal VLAN representation on FastEthernet0/0:

VLAN Id: 1    (.1Q, Fa0/0)

VLAN Id: 201  (.1Q-in-.1Q tree, 3 elements)

  Inner VLAN Id: (0   -0   ) Fa0/0.201

  dot1q software subblock bitlist missing

  Inner VLAN Id: (2001-2001) Fa0/0.2012001

  2001

  Inner VLAN Id: (2002-2002) Fa0/0.2012002

  2002

  "any" Fa0/0.201999

VLAN Id: 401  (.1Q-in-.1Q tree, 3 elements)

  Inner VLAN Id: (0   -0   ) Fa0/0.401

  dot1q software subblock bitlist missing

  Inner VLAN Id: (100 -900 ) Fa0/0.4019999

  100-900,1001-2000

  Inner VLAN Id: (1001-2000) Fa0/0.4019999

  100-900,1001-2000

Internal VLAN representation on GigabitEthernet5/0:

VLAN Id: 1    (.1Q, Gi5/0)

VLAN Id: 101  (.1Q-in-.1Q tree, 5 elements)

  Inner VLAN Id: (0   -0   ) Gi5/0.101

  dot1q software subblock bitlist missing

  Inner VLAN Id: (1   -1000) Gi5/0.1019999

  1-1000,1003-2000

  Inner VLAN Id: (1001-1001) Gi5/0.1011001

  1001

  Inner VLAN Id: (1002-1002) Gi5/0.1011002

  1002

  Inner VLAN Id: (1003-2000) Gi5/0.1019999

  1-1000,1003-2000

VLAN Id: 301  (.1Q-in-.1Q tree, 1 elements)

  Inner VLAN Id: (0   -0   ) Gi5/0.301

  dot1q software subblock bitlist missing

  "any" Gi5/0.301999

Related Commands

Command	Description
encapsulation dot1q	Enables IEEE 802.1q encapsulation of traffic on a specified subinterface in a VLAN.
vlan (VLAN configuration mode)	Configures a specific VLAN.
vlan database	Enters VLAN configuration mode.

show vlans

To view virtual LAN (VLAN) subinterfaces, use the show vlans command in privileged EXEC mode.

show vlans

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC

Command History

Release	Modification
11.0	This command was introduced.
12.1(3)T	This command was modified to display traffic count on FastEthernet subinterfaces.

Examples

The following is sample output from the show vlans command indicating a native VLAN and a bridged group:

Virtual LAN ID:  1 (IEEE 802.1Q Encapsulation)

   vLAN Trunk Interface:   FastEthernet1/0/2

 This is configured as native Vlan for the following interface(s) :

FastEthernet1/0/2

   Protocols Configured:   Address: Received:        Transmitted:

Virtual LAN ID:  100 (IEEE 802.1Q Encapsulation)

   vLAN Trunk Interface:   FastEthernet1/0/2.1

   Protocols Configured:   Address: Received:        Transmitted:

        Bridging        Bridge Group 1 0                   0

The following is sample output from the show vlans command that shows the traffic count on Fast Ethernet subinterfaces:

Router# show vlans

Virtual LAN ID:  2 (IEEE 802.1Q Encapsulation)

    vLAN Trunk Interface:   FastEthernet5/0.1

    Protocols Configured:   Address:              Received:        Transmitted:

            IP              56.0.0.3                    16               92129

Virtual LAN ID:  3 (IEEE 802.1Q Encapsulation)

    vLAN Trunk Interface:   Ethernet6/0/1.1

    Protocols Configured:   Address:              Received:        Transmitted:

            IP              36.0.0.3                  1558                1521

Virtual LAN ID:  4 (Inter Switch Link Encapsulation)

    vLAN Trunk Interface:   FastEthernet5/0.2     

    Protocols Configured:   Address:              Received:        Transmitted:

            IP              76.0.0.3                     0                   7

Table 10 describes the significant fields shown in the display.

Table 10 show vlans Field Descriptions  

Field	Description
Virtual LAN ID	Domain number of the VLAN.
vLAN Trunk Interface	Subinterface that carries the VLAN traffic.
Protocols Configured	Protocols configured on the VLAN.
Address	Network address.
Received	Packets received.
Transmitted	Packets sent.

Related Commands

Command	Description
vlan (VLAN configuration mode)	Configures a specific VLAN.
vlan database	Enters VLAN configuration mode.

show vlan-switch

To display virtual LAN (VLAN) information, use the show vlan-switch command in privileged EXEC mode.

show vlan-switch [brief | id vlan | name name]

Syntax Description

brief	(Optional) Displays only a single line for each VLAN, naming the VLAN, status, and ports.
id vlan	(Optional) Displays information about a single VLAN identified by VLAN ID number; valid values are from 1 to 1005.
name name	(Optional) Displays information about a single VLAN identified by VLAN name; valid values are an ASCII string from 1 to 32 characters.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.2(2)XT	This command was introduced on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(8)T	This command was integrated into Cisco IOS Release 12.2(8)T on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.

Usage Guidelines

Each Ethernet switch port and Ethernet repeater group belongs to only one VLAN. Trunk ports can be on multiple VLANs.

Examples

The following example shows how to display the VLAN parameters for all VLANs within the administrative domain:

Router# show vlan-switch

VLAN Name                             Status    Ports

---- -------------------------------- --------- -------------------------------

1    default                          active    Fa4/0, Fa4/1, Fa4/2, Fa4/3

                                                Fa4/4, Fa4/5, Fa4/6, Fa4/7

                                                Fa4/8, Fa4/9, Fa4/10, Fa4/11

                                                Fa4/12, Fa4/13, Fa4/14, Fa4/15

                                                Fa4/16, Fa4/17, Fa4/18, Fa4/19

                                                Fa4/20, Fa4/21, Fa4/22, Fa4/23

                                                Fa4/24, Fa4/25, Fa4/26, Fa4/27

                                                Fa4/28, Fa4/29, Fa4/30, Fa4/31

                                                Fa4/32, Fa4/33, Fa4/34, Fa4/35

                                                Gi4/0, Gi4/1, Po1

2    VLAN0002                         active    

3    VLAN0003                         active    

5    VLAN0005                         active    

1002 fddi-default                     active    

1003 token-ring-default               active    

1004 fddinet-default                  active    

1005 trnet-default                    active    

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2

---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------

1    enet  100001     1500  -      -      -        -    -        1002   1003

2    enet  100002     1500  -      -      -        -    -        0      0   

3    enet  100003     1500  -      -      -        -    -        0      0   

5    enet  100005     1500  -      -      -        -    -        0      0   

1002 fddi  101002     1500  -      0      -        -    -        1      1003

1003 tr    101003     1500  1005   0      -        -    srb      1      1002

1004 fdnet 101004     1500  -      -      1        ibm  -        0      0   

1005 trnet 101005     1500  -      -      1        ibm  -        0      0 

Table 11 describes the significant fields shown in the display.

Table 11 show vlan Field Descriptions 

Field	Description
VLAN	VLAN number.
Name	Name, if configured, of the VLAN.
Status	Status of the VLAN (active or suspend).
Ports	Ports that belong to the VLAN.
Type	Media type of the VLAN.
SAID	Security association ID value for the VLAN.
MTU	Maximum transmission unit size for the VLAN.
Parent	Parent VLAN, if one exists.
RingNo	Ring number for the VLAN, if applicable.
BrdgNo	Bridge number for the VLAN, if applicable.
Stp	Spanning-Tree Protocol type used on the VLAN.
BrdgMode	Bridging mode for this VLAN—possible values are source-route bridging (SRB) and source-route transparent bridging (SRT); the default is SRB.
Trans1, Trans2	Types of translational bridges that the VLAN in the VLAN column is configured to translate to. Translational bridge VLANs must be a VLAN media type different from the affected VLAN; if two VLANs are specified, each one must be a different type. Common VLAN types include Ethernet (enet), FDDI (fdnet), and Token Ring (tnet). The numbers in the "Trans1" and "Trans2" columns refer to the VLAN ID numbers of the translational bridge VLANs. Note The term "VLAN translation" is also used in Cisco configuration guides for mapping specific VLANs in a given trunk to another VLAN that is of the same media type. In this context the term VLAN translation refers to a form of VLAN mapping that is using the term "VLAN translation" to describe it.>

show vtp

To display general information about the virtual LAN (VLAN) Trunk Protocol (VTP) management domain, status, and counters, use the show vtp command in privileged EXEC mode.

show vtp {counters | status}

Syntax Description

counters	Displays the VTP counters for the switch.
status	Displays the general information about the VTP management domain.

Command Modes

Privileged EXEC

Command History

Release	Modification
11.2(8)SA4	This command was introduced.
12.2(2)XT	This command was implemented on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(8)T	This command was integrated into Cisco IOS Release 12.2(8)T on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.

Examples

The following is sample output from the show vtp counters command:

Router# show vtp counters

VTP statistics:

Summary advertisements received    : 38

Subset advertisements received     : 0

Request advertisements received    : 0

Summary advertisements transmitted : 13

Subset advertisements transmitted  : 3

Request advertisements transmitted : 0

Number of config revision errors   : 0

Number of config digest errors     : 0

Number of V1 summary errors        : 0

VTP pruning statistics:

Trunk            Join Transmitted Join Received    Summary advts received from

                                                   non-pruning-capable device

---------------- ---------------- ---------------- ---------------------------

Fa0/9               827              824              0

Fa0/10              827              823              0 

Fa0/11              827              823              0

Table 12 describes the significant fields shown in the display.

Table 12 show vtp counters Field Descriptions 

Field	Description
Summary advertisements received	Number of summary advertisements received by this switch on its trunk ports. Summary advertisements contain the management domain name, the configuration revision number, the update time stamp and identity, the authentication checksum, and the number of subset advertisements to follow.
Subset advertisements received	Number of subset advertisements received by this switch on its trunk ports. Subset advertisements contain all the information for one or more VLANs.
Request advertisements received	Number of advertisement requests received by this switch on its trunk ports. Advertisement requests normally request information on all VLANs. They can also request information on a subset of VLANs.
Summary advertisements transmitted	Number of summary advertisements sent by this switch on its trunk ports. Summary advertisements contain the management domain name, the configuration revision number, the update timestamp and identity, the authentication checksum, and the number of subset advertisements to follow.
Subset advertisements transmitted	Number of subset advertisements sent by this switch on its trunk ports. Subset advertisements contain all the information for one or more VLANs.
Request advertisements transmitted	Number of advertisement requests sent by this switch on its trunk ports. Advertisement requests normally request information on all VLANs. They can also request information on a subset of VLANs.
Number of config revision errors	Number of revision errors. Whenever you define a new VLAN, delete an existing VLAN, suspend or resume an existing VLAN, or modify the parameters on an existing VLAN, the configuration revision number of the switch increments. Revision errors increment whenever the switch receives an advertisement whose revision number matches the revision number of the switch, but the MD5 digest values do not match. This error indicates that the VTP password in the two switches is different, or the switches have different configurations. These errors indicate that the switch is filtering incoming advertisements, which causes the VTP database to become unsynchronized across the network.
Number of config digest errors	Number of MD5 digest errors. Digest errors increment whenever the MD5 digest in the summary packet and the MD5 digest of the received advertisement calculated by the switch do not match. This error usually indicates that the VTP password in the two switches is different. To solve this problem, make sure the VTP password on all switches is the same. These errors indicate that the switch is filtering incoming advertisements, which causes the VTP database to become unsynchronized across the network.
Number of V1 summary errors	Number of version 1 errors. Version 1 summary errors increment whenever a switch in VTP V2 mode receives a VTP version 1 frame. These errors indicate that at least one neighboring switch is either running VTP version 1 or VTP version 2 with V2-mode disabled. To solve this problem, change the configuration of the switches in VTP V2-mode to disabled.
Join Transmitted	Number of VTP pruning messages transmitted on the trunk.
Join Received	Number of VTP pruning messages received on the trunk.
Summary Advts Received from non-pruning-capable device	Number of VTP summary messages received on the trunk from devices that do not support pruning.

The following is sample output from the show vtp status command:

Router# show vtp status

VTP Version                     : 2

Configuration Revision          : 1

Maximum VLANs supported locally : 68

Number of existing VLANs        : 7

VTP Operating Mode              : Server

VTP Domain Name                 : test1

VTP Pruning Mode                : Disabled

VTP V2 Mode                     : Disabled

VTP Traps Generation            : Disabled

MD5 digest                      : 0x3D 0x02 0xD4 0x3A 0xC4 0x46 0xA1 0x03

Configuration last modified by 172.20.130.52 at 3-4-93 22:25:

Table 13 describes the significant fields shown in the display.

Table 13 show vtp status Field Descriptions 

Field	Description
VTP Version	Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers Displays the VTP version operating on the switch. By default, switches implement version 1. Catalyst Switches Displays the VTP version operating on the switch. By default, Catalyst 2900 and 3500 XL switches implement version 1 but can be set to version 2.
Configuration Revision	Current configuration revision number on this switch.
Maximum VLANs Supported Locally	Maximum number of VLANs supported locally.
Number of Existing VLANs	Number of existing VLANs.
VTP Operating Mode	Displays the VTP operating mode, which can be server, client, or transparent. Server—A switch in VTP server mode is enabled for VTP and sends advertisements. You can configure VLANs on it. The switch guarantees that it can recover all VLAN information in the current VTP database from nonvolatile storage after reboot. By default, every switch is a VTP server. Client—A switch in VTP client mode is enabled for VTP, can send advertisements, but does not have enough nonvolatile storage to store VLAN configurations. You cannot configure VLANs on it. When a VTP client starts up, it does not transmit VTP advertisements until it receives advertisements to initialize its VLAN database. Transparent—A switch in VTP transparent mode is disabled for VTP, does not transmit advertisements or learn from advertisements sent by other devices, and cannot affect VLAN configurations on other devices in the network. The switch receives VTP advertisements and forwards them on all trunk ports except the one on which the advertisement was received. The configuration of multi-VLAN ports causes the switch to automatically enter transparent mode. Note Catalyst 2912MF, 2924M, and 3500 XL switches support up to 250 VLANs. All other Catalyst 2900 XL switches support up to 64 VLANs. If you define more than 250 or 64 or if the switch receives an advertisement that contains more than 250 or 64 VLANs, the switch automatically enters VTP transparent mode and operates with the VLAN configuration preceding the one that sent it into transparent mode. Note Catalyst 2912MF, 2924M, and 3500 XL switches support up to 250 VLANs. All other Catalyst 2900 XL switches support up to 64 VLANs. For Catalyst 2912MF, 2924M, and 3500 XL switches, if you define more than 250 or if the switch receives an advertisement that contains more than 250 VLANs, the switch automatically enters VTP transparent mode and operates with the VLAN configuration preceding the one that sent it into transparent mode. For all other Catalyst 2900 XL switches, if you define more than 64 or if the switch receives an advertisement that contains more than 64 VLANs, the switch automatically enters VTP transparent mode and operates with the VLAN configuration preceding the one that sent it into transparent mode.
VTP Domain Name	Name that identifies the administrative domain for the switch.
VTP Pruning Mode	Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers VTP pruning mode is not supported on the Cisco 2600 series and Cisco 3600 series routers. Catalyst Switches Displays whether pruning is enabled or disabled. Enabling pruning on a VTP server enables pruning for the entire management domain. Pruning restricts flooded traffic to those trunk links that the traffic must use to access the appropriate network devices.
VTP V2 Mode	Displays if VTP version 2 mode is enabled. All VTP version 2 switches operate in version 1 mode by default. Each VTP switch automatically detects the capabilities of all other VTP devices. A network of VTP devices should be configured to version 2 only if all VTP switches in the network can operate in version 2 mode.
VTP Traps Generation	Displays whether VTP traps are transmitted to a network management station.
MD5 Digest	16-byte checksum of the VTP configuration.
Configuration Last Modified	Displays the date and time of the last configuration modification. Displays the IP address of the switch that caused the configuration change to the database.

Related Commands

Command	Description
clear vtp counters	Clears the VTP and pruning counters.
vtp	Configures the VTP mode.

spanning-tree backbonefast

To enable the BackboneFast feature, use the spanning-tree backbonefast command in global configuration mode. To return to the default setting, 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

Release	Modification
12.1(6)EA2	This command was introduced.
12.2(15)ZJ	This command was implemented on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.3(4)T	This command was integrated into Cisco IOS Release 12.3(4)T on the following platforms: Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.

Usage Guidelines

BackboneFast should be enabled on all of the Cisco routers containing an Ethernet switch network module. BackboneFast provides for fast convergence in the network backbone after a spanning-tree topology change. It enables the switch to detect an indirect link failure and to start the spanning-tree reconfiguration sooner than it would under normal spanning-tree rules.

Use the show spanning-tree privileged EXEC command to verify your settings.

Examples

The following example shows how to enable BackboneFast on the switch:

Router(config)# spanning-tree backbonefast

Related Commands

Command	Description
show spanning-tree	Displays spanning-tree information for the specified spanning-tree instances.

spanning-tree cost

To set the path cost of the interface for Spanning Tree Protocol (STP) calculations, use the spanning-tree cost command in interface configuration mode. To revert to the default value, use the no form of this command.

spanning-tree cost cost

no spanning-tree cost

Syntax Description

cost	Path cost; valid values are from 1 to 200000000 for Cisco IOS Releases 12.1(3a)E and later releases and from 1 to 65535 for Cisco IOS releases prior to Cisco IOS Release 12.1(3a)E.

Defaults

The default path cost is computed from the bandwidth setting of the interface; default path costs are:

Ethernet: 100
16-Mb Token Ring: 62
FDDI: 10
FastEthernet: 10
ATM 155: 6
GigibitEthernet: 1
HSSI: 647

Command Modes

Interface configuration

Command History

Release	Modification
12.0(7)XE	This command was introduced on the Catalyst 6000 family switches.
12.1(3a)E	This command was modified to support 32-bit path cost.
12.2(2)XT	This command was introduced on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(8)T	This command was integrated into Cisco IOS Release 12.2(8)T on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.

Usage Guidelines

When you specify a value for the cost argument, higher values indicate higher costs. This range applies regardless of the protocol type specified.

Examples

The following example shows how to access an interface and set a path cost value of 250 for the spanning tree VLAN associated with that interface:

Router(config)# interface ethernet 2/0

Router(config-if)# spanning-tree cost 250

Related Commands

Command	Description
show spanning-tree	Displays spanning-tree information for the specified spanning-tree instances.
spanning-tree port-priority	Sets an interface priority when two bridges tie for position as the root bridge.
spanning-tree portfast (global configuration mode)	Enables PortFast mode, where the interface is immediately put into the forwarding state upon linkup without waiting for the timer to expire.
spanning-tree portfast (interface configuration mode)	Enables PortFast mode, where the interface is immediately put into the forwarding state upon linkup without waiting for the timer to expire.
spanning-tree uplinkfast	Enables the UplinkFast feature.
spanning-tree vlan	Configures STP on a per-VLAN basis.

spanning-tree port-priority

To set an interface priority when two bridges tie for position as the root bridge, use the spanning-tree port-priority command in interface configuration mode. To revert to the default value, use the no form of this command.

spanning-tree port-priority port-priority

no spanning-tree port-priority

Syntax Description

port-priority

Port priority; valid values are from 2 to 255. The default is 128.

Defaults

The port priority is 128.

Command Modes

Interface configuration

Command History

Release	Modification
12.0(7)XE	This command was introduced on the Catalyst 6000 family switches.
12.2(2)XT	This command was implemented on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(8)T	This command was integrated into Cisco IOS Release 12.2(8)T on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.

Usage Guidelines

The priority you set breaks the tie.

Examples

The following example shows how to increase the likelihood that the spanning tree instance 20 is chosen as the root-bridge on interface ethernet 2/0:

Router(config)# interface ethernet 2/0

Router(config-if)# spanning-tree port-priority 20

Router(config-if)#

Related Commands

Command	Description
show spanning-tree	Displays spanning-tree information for the specified spanning-tree instances.
spanning-tree cost	Sets the path cost of the interface for STP calculations.
spanning-tree portfast (global configuration mode)	Enables PortFast mode, where the interface is immediately put into the forwarding state upon linkup without waiting for the timer to expire.
spanning-tree portfast (interface configuration mode)	Enables PortFast mode, which places the interface immediately into the forwarding state upon linkup without waiting for the timer to expire.
spanning-tree uplinkfast	Enables the UplinkFast feature.
spanning-tree vlan	Configures STP on a per-VLAN basis.

spanning-tree vlan

To configure Spanning Tree Protocol (STP) on a per-virtual LAN (VLAN) basis, use the spanning-tree vlan command in global configuration mode. 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 | protocol | root]

Syntax Description

vlan-id	VLAN identification number; valid values are from 1 to 1005.
forward-time seconds	(Optional) Sets the STP forward delay time; valid values are from 4 to 30 seconds.
hello-time seconds	(Optional) Specifies in seconds, the duration between the generation of configuration messages by the root switch; valid values are from 1 to 10 seconds.
max-age seconds	(Optional) Sets the maximum number of seconds the information in a bridge packet data unit (BPDU) is valid; valid values are from 6 to 40 seconds.
priority priority	(Optional) Sets the STP bridge priority; valid values are from 0 to 65535.
protocol protocol	(Optional) Sets the STP. See the "Usage Guidelines" section for a list of valid values.
root primary	(Optional) Forces this switch to be the root bridge.
root secondary	(Optional) Specifies this switch to act as the root switch should the primary root fail.
diameter net-diameter	(Optional) Specifies the maximum number of bridges between any two points of attachment of end stations; valid values are from 2 through 7.

Defaults

forward-time: 15 seconds
hello-time: 2 seconds
max-age: 20 seconds
priority: The default with IEEE STP enabled is 32,768; with STP enabled, the default is 128.
protocol: IEEE
root: No STP root

Command Modes

Global configuration

Command History

Release	Modification
12.0(7)XE	This command was introduced on the Catalyst 6000 family switches.
12.1(1)E	Support for this command on the Catalyst 6000 family switches was extended to the E train.
12.2(2)XT	This command was implemented on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(8)T	This command was integrated into Cisco IOS Release 12.2(8)T on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.

Usage Guidelines

When setting the max-age seconds, if a bridge does not hear Bridge Protocol Data Units (BPDU) from the root bridge within the specified interval, it assumes that the network has changed and recomputes the spanning tree topology.

Valid values for protocol are dec (Digital STP), ibm (IBM STP), ieee (IEEE Ethernet STP), and vlan-bridge (VLAN Bridge STP).

The spanning-tree root primary command alters this switch's bridge priority to 8,192. If you enter after 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 results.

The spanning-tree root secondary command alters this switch's bridge priority to 16,384. If the root switch should fail, this switch becomes the next root switch.

Use the spanning-tree root commands on backbone switches only.

Examples

The following example shows how to enable spanning tree on VLAN 200:

Router(config)# spanning-tree vlan 200 

The following example shows how to configure the switch as the root switch for VLAN 10 with a network diameter of 4:

Router(config)# spanning-tree vlan 10 root primary diameter 4 

The following example shows how to configure the switch as the secondary root switch for VLAN 10 with a network diameter of 4:

Router(config)# spanning-tree vlan 10 root secondary diameter 4 

Related Commands

Command	Description
show spanning-tree	Displays spanning-tree information for the specified spanning-tree instances.
spanning-tree cost	Sets the path cost of the interface for STP calculations.
spanning-tree port-priority	Sets an interface priority when two bridges tie for position as the root bridge.
spanning-tree portfast (global configuration mode)	Enables PortFast mode, where the interface is immediately put into the forwarding state upon linkup, without waiting for the timer to expire.
spanning-tree portfast (interface configuration mode)	Enables PortFast mode, where the interface is immediately put into the forwarding state upon linkup, without waiting for the timer to expire.
spanning-tree uplinkfast	Enables the UplinkFast feature.