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bridge-domain through instance VLAN
- bridge-domain
- bridge-domain (subinterface)
- bridge-vlan
- clear gvrp statistics
- clear mac-address-table
- clear mvr counters
- clear mvrp statistics
- clear pagp
- clear spanning-tree detected-protocol
- clear vlan
- clear vlan counters
- clear vlan mapping
- clear vlan statistics
- clear vtp counters
- collect top counters interface
- debug udld
- dot1q tunneling ethertype
- encapsulation dot1q
- encapsulation isl
- encapsulation sde
- flowcontrol
- flowcontrol (line)
- flowcontrol receive
- gvrp global
- gvrp mac-learning auto
- gvrp registration
- gvrp timer
- gvrp vlan create
- hw-module slot (ASR 1000 Series)
- instance (VLAN)
- l2protocol forward
bridge-domain
To enable RFC 1483 ATM bridging or RFC 1490 Frame Relay bridging to map a bridged VLAN to an ATM permanent virtual circuit (PVC) or Frame Relay data-link connection identifier (DLCI), use the bridge-domaincommand in Frame Relay DLCI configuration, interface configuration, interface ATM VC configuration, or PVC range configuration mode. To disable bridging, use the no form of this command.
bridge-domain vlan-id [ access | dot1q [tag] | dot1q-tunnel ] [broadcast] [ignore-bpdu-pid] [ pvst-tlv CE-vlan ] [increment] [lan-fcs] [split-horizon]
no bridge-domain vlan-id
Syntax Description
Command Modes
Frame Relay DLCI configuration (config-fr-dlci) Interface configuration (config-if)--Only the dot1q and dot1q-tunnel keywords are supported in interface configuration mode. Interface ATM VC configuration (config-if-atm-vc) PVC range configuration (config-if-atm-range)
Command History
Release
Modification
12.1(13)E
This command was introduced as the bridge-vlan command for the 2-port OC-12 ATM WAN Optical Services Modules (OSMs) on Cisco 7600 series routers and Catalyst 6500 series switches.
12.1(12c)E
This command was integrated into Cisco IOS Release 12.1(12c)E.
12.1(14)E1
This command was integrated into Cisco IOS Release 12.1(14)E1. The dot1q-tunnel keyword was added.
12.2(14)SX
This command was integrated into Cisco IOS Release 12.2(14)SX. The dot1q-tunnel keyword is not supported in this release.
12.1(19)E
The split-horizon keyword was added.
12.2(18)S
This command was integrated into Cisco IOS Release 12.2(18)S. The dot1q-tunnel and split-horizon keywords are supported in this release.
12.2(17a)SX
Support was added for the dot1q-tunnel keyword in Cisco IOS Release 12.2(17a)SX.
12.2(18)SXE
This command was renamed from bridge-vlan to bridge-domain. The access, broadcast, ignore-bpdu-pid, and increment keywords were added.
12.2(18)SXF2
Support for the lan-fcs and broadcastkeywords was removed. The ignore-bpdu-pidand pvst-tlvkeywords were added.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
Usage Guidelines
RFC 1483 bridging on ATM interfaces supports the point-to-point bridging of Layer 2 packet data units (PDUs) over Ethernet networks. RFC 1490 Frame Relay bridging on Packet over SONET (POS) or serial interfaces that are configured for Frame Relay encapsulation provides bridging of Frame Relay packets over Ethernet networks.
The Cisco 7600 router can transmit BPDUs with a PID of either 0x00-0E or 0x00-07. When the router connects to a device that is fully compliant with RFC 1483 Appendix B, in which the IEEE BPDUs are sent and received by the other device using a PID of 0x00-0E, you must not use the ignore-bpdu-pidkeyword.
If you do not enter the ignore-bpdu-pid keyword, the PVC between the devices operates in compliance with RFC 1483 Appendix B. This is referred to as strict mode . Entering the ignore-bpdu-pid keyword creates loose mode . Both modes are described as follows:
- Without the ignore-bpdu-pidkeyword, in strict mode, IEEE BPDUs are sent out using a PID of 0x00-0E, which complies with RFC 1483.
- With the ignore-bpdu-pidkeyword, in loose mode, IEEE BPDUs are sent out using a PID of 0x00-07, which is normally reserved for RFC 1483 data.
Cisco-proprietary PVST+ BPDUs are always sent out on data frames using a PID of 0x00-07, regardless of whether you enter the ignore-bpdu-pid keyword.
Use the ignore-bpdu-pid keyword when connecting to devices such as ATM digital subscriber line (DSL) modems that send PVST (or 802.1D) BPDUs with a PID of 0x00-07.
The pvst-tlv keyword enables BPDU translation when the router interoperates with devices that understand only PVST or IEEE Spanning Tree Protocol. Because the Catalyst 6500 series switch ATM modules support PVST+ only, you must use the pvst-tlv keyword when connecting to a Catalyst 5000 family switch that understands only PVST on its ATM modules, or when connecting with other Cisco IOS routers that understand IEEE format only.
When the router or switch is transmitting, the pvst-tlv keyword translates PVST+ BPDUs into IEEE BPDUs.
When the router or switch is receiving, the pvst-tlv keyword translates IEEE BPDUs into PVST+ BPDUs.
NoteThe bridge-domainand bre-connect commands are mutually exclusive. You cannot use both commands on the same PVC for concurrent RFC 1483 and BRE bridging.
To preserve class of service (CoS) information across the ATM network, use the dot1q option. This configuration uses IEEE 802.1Q tagging to preserve the VLAN ID and packet headers as they are transported across the ATM network.
To enable service providers to use a single VLAN to support customers that have multiple VLANs, while preserving customer VLAN IDs and segregating traffic in different customer VLANs, use the dot1q-tunnel option on the service provider router. Then use the dot1q option on the customer routers.
NoteThe access, dot1q, and dot1q-tunnel options are mutually exclusive. If you do not specify any of these options, the connection operates in “raw” bridging access mode, which is similar to access, except that the connection does act on and transmit BPDU packets.
RFC 1483 bridging is supported on AAL5-MUX and AAL5-LLC Subnetwork Access Protocol (SNAP) encapsulated PVCs. RFC-1483 bridged PVCs must terminate on the ATM interface, and the bridged traffic must be forwarded over an Ethernet interface, unless the split-horizon option is used, which allows bridging of traffic across bridged PVCs.
NoteRFC 1483 bridging is not supported for switched virtual circuits (SVCs). It also cannot be configured for PVCs on the main interface.
In interface configuration mode, only the dot1q and dot1q-tunnel keyword options are supported.
Examples
The following example shows a PVC being configured for IEEE 802.1Q VLAN bridging using a VLAN ID of 99:
Router# configure terminal Router(config)# interface ATM6/2 Router(config-if)# pvc 2/101 Router(config-if-atm-vc)# bridge-domain 99 dot1q Router(config-if-atm-vc)# endThe following example shows how to enable BPDU translation when a Catalyst 6500 series switch is connected to a device that understands only IEEE BPDUs in an RFC 1483-compliant topology:
Router(config-if-atm-vc)# bridge-domain 100 pvst-tlv 150The ignore-bpdu-pid keyword is not used because the device operates in an RFC 1483-compliant topology for IEEE BPDUs.
The following example shows how to enable BPDU translation when a Catalyst 5500 ATM module is a device that understands only PVST BPDUs in a non-RFC1483-compliant topology. When a Catalyst 6500 series switch is connected to a Catalyst 5500 ATM module, you must enter both keywords.
Router(config-if-atm-vc)# bridge-domain 100 ignore-bpdu-pid pvst-tlv 150To enable BPDU translation for the Layer 2 Protocol Tunneling ( L2PT) topologies, use the following command:
Router(config-if-atm-vc)# bridge-domain 100 dot1q-tunnel ignore-bpdu-pid pvst-tlv 150The following example shows a range of PVCs being configured, with the bridge domain number being incremented for each PVC in the range:
Router(config)# interface atm 8/0.100 Router(config-if)# range pvc 102/100 102/199 Router(config-if-atm-range)# bridge-domain 102 incrementbridge-domain (subinterface)
To enable bridging across Gigabit Ethernet subinterfaces, use the bridge-domaincommand in subinterface configuration mode. To disable bridging, use the no form of this command.
bridge-domain vlan-id { dot1q | dot1q-tunnel } [ bpdu { drop | transparent } ] [split-horizon]
no bridge-domain vlan-id { dot1q | dot1q-tunnel } [ bpdu { drop | transparent } ] [split-horizon]
Syntax Description
vlan-id
Specifies the number of the virtual LAN (VLAN) to be used in this bridging configuration. The valid range is from 2 to 4094.
dot1q
Enables IEEE 802.1Q tagging to preserve the class of service (CoS) information from the Ethernet frames across the ATM network. If not specified, the ingress side assumes a CoS value of 0 for QoS purposes.
dot1q-tunnel
Enables IEEE 802.1Q tunneling mode, so that service providers can use a single VLAN to support customers who have multiple VLANs, while preserving customer VLAN IDs and keeping traffic in different customer VLANs segregated.
bpdu {drop | transparent}
(Optional) Specifies whether or not BPDUs are processed or dropped:
- drop --Specifies that BPDU packets are dropped on the subinterface.
- transparent --Specifies that BPDU packets are forwarded as data on the subinterface, but not processed.
split-horizon
(Optional) Enables RFC 1483 split horizon mode to globally prevent bridging between PVCs in the same VLAN.
Usage Guidelines
This command has the following restrictions in Cisco IOS Release 12.2(33)SRA:
- The command is available on the Cisco 7600 SIP-400 with a 2-Port Gigabit Ethernet SPA only.
- You can place up to 120 subinterfaces in the same bridge domain on a single Cisco 7600 SIP-400.
To enable service providers to use a single VLAN to support customers who have multiple VLANs, while preserving customer VLAN IDs and keeping traffic in different customer VLANs segregated, use the dot1q-tunnel option on the service provider router. Then use the dot1q option on the customer routers.
Examples
The following example shows configuration of IEEE 802.1Q encapsulation for VLANs on Gigabit Ethernet subinterfaces with configuration of multipoint bridging (MPB). The MPB feature requires configuration of 802.1Q encapsulation on the subinterface.
The first subinterface bridges traffic on VLAN 100 and preserves CoS information in the packets by specifying the dot1q keyword.
Router(config)# interface GigabitEthernet 1/0/1.1 Router(config-subif)# encapsulation dot1q 10 Router(config-subif)# bridge-domain 100 dot1qThe second subinterface shows bridging of traffic on VLAN 200 in tunneling mode using the dot1q-tunnel keyword, which preserves the VLAN IDs of the bridged traffic.
Router(config)# interface GigabitEthernet 2/0/2.2 Router(config-subif)# encapsulation dot1q 20 Router(config-subif)# bridge-domain 200 dot1q-tunnelThe following example shows bridging of traffic from different VLANs on two separate Gigabit Ethernet subinterfaces into the same VLAN. First, the bridging VLAN 100 is created using the vlan command. Then, the Gigabit Ethernet subinterfaces implement IEEE 802.1Q encapsulation on VLAN 10 and VLAN 20 and bridge the traffic from those VLANs onto VLAN 100 using the bridge-domain command:
Router(config)# vlan 100 Router(config-vlan)# exit ! Router(config)# interface GigabitEthernet 1/0/1.1 Router(config-subif)# encapsulation dot1q 10 Router(config-subif)# bridge-domain 100 dot1q Router(config-subif)# exit ! Router(config)# interface GigabitEthernet 1/0/2.1 Router(config-subif)# encapsulation dot1q 20 Router(config-subif)# bridge-domain 100 dot1qbridge-vlan
To map a subinterface to specific inner customer-edge and outer provider-edge VLAN tags using 802.1Q-in-802.1Q (QinQ) translation, use the bridge-vlancommand in subinterface configuration mode. To remove the QinQ VLAN mapping, use the no form of this command.
bridge-vlan vlan-id { dot1q | dot1q-tunnel } { inner-vlan-id | out-range }
no bridge-vlan vlan-id { dot1q | dot1q-tunnel } { inner-vlan-id | out-range }
Syntax Description
vlan-id
Outer provider-edge VLAN ID to be mapped; valid values are from 1 to 4094, except for the reserved IDs from 1002 through 1005.
dot1q
Specifies that the inner customer-edge and outer provider-edge VLAN tags on incoming packets are replaced with a single trunk VLAN tag on the outgoing Ethernet frames.
dot1q-tunnel
Specifies that the outer provider-edge VLAN tag on incoming packets is replaced with a trunk VLAN tag on the outgoing Ethernet frames.
inner-vlan-id
Inner customer-edge VLAN ID to be mapped; valid values are from 1 to 4094, except for the reserved IDs from 1002 through 1005.
out-range
Specifies that all customer-edge VLAN IDs that are outside of the range of 32 VLAN IDs are mapped for this provider-edge VLAN ID. See the “Usage Guidelines” section for additional information.
Command Default
- No bridged VLANs are configured.
- Packets with out-of-range or missing customer-edge VLANs are dropped.
Command History
Release
Modification
12.2(18)SXD
Support for this command was introduced on the Supervisor Engine 720.
12.2(18)SXE
This command was replaced by the bridge-domain(subinterface) command. See the “Usage Guidelines” section for more information.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
Usage Guidelines
The bridge-vlan command is supported only on subinterfaces of the Gigabit Ethernet WAN (GE-WAN) interfaces that are on the OSM-2+4GE-WAN+ OSM. The command cannot be used on other modules or on Gigabit Ethernet (GE) LAN interfaces.
You must have previously enabled QinQ translation on the main interface using the modedot1q-in-dot1qaccess-gateway command before you can use the bridge-vlan command on a subinterface.
You must also use the encapsulationdot1q command on the subinterface to specify the trunk VLAN to use on outgoing packets.
Cisco IOS Release 12.2(18)SXE automatically replaces any use of the bridge-vlan command in previous QinQ configurations to the bridge-domain command.
NoteWhen upgrading from Cisco IOS Release 12.2(18)SXD to Cisco IOS Release 12.2(18)SXE, be sure to save your running configuration to NVRAM using the writememory or copyrunning-configstartup-config command so that you will save the QinQ configurations when you enter the bridge-domain command.
Each provider-edge VLAN supports a maximum of 32 customer-edge VLANs, which must be in a contiguous block that starts on a number divisible by 32 (for example: 0, 32, 64, and so forth). When you specify the first customer-edge VLAN ID for a provider-edge VLAN, the Cisco IOS software automatically associates the corresponding block of 32 IDs with that provider-edge VLAN.
VLAN 4095 is reserved and cannot be used as a customer-edge VLAN. Packets that contain a customer-edge VLAN ID of 4095 are automatically dropped by subinterfaces that are configured for QinQ translation. However, VLAN 4095 can continue to be used as a native (non-QinQ) VLAN.
A provider-edge VLAN cannot have the same ID as a native (non-QinQ) VLAN that is also being used on the router.
Entering the dot1q keyword results in QinQ translation, which is also known as a double-tag to single-tag translation.
When you enter the dot1q-tunnelkeyword, the inner customer-edge tag is left unchanged. This results in transparent tunneling, which is also known as a double-tag to double-tag translation.
The out-rangekeyword is allowed only if you enter the dot1q-tunnel keyword.
You can use the out-rangekeyword to match the packets that do not have a customer-edge VLAN tag.
802.1Q provides for a trunking option that tags packets with two VLAN tags to allow multiple VLANs to be trunked together across an intermediate network. This use of a double-tagged tunnel is called QinQ tunneling.
For additional information, refer to the OpticalServicesModuleInstallationandConfigurationNote.
Examples
This example shows how to configure a double-tag-to-single-tag translation of packets that are tagged with both an inner customer-edge VLAN of 41 and an outer provider-edge VLAN of 33. The translated outgoing packets have a single trunk VLAN tag of 100.
Router# configure terminal Router(config)# interface GE-WAN 4/1.100 Router(config-subif)# encapsulation dot1q 100 Router(config-subif)# bridge-vlan 33 dot1q 41 Router(config-subif)#
NoteThe above configuration also associates the block of 32 customer-edge VLANs ranging from 32 to 63 with provider-edge VLAN 33. All other customer-edge VLAN IDs are considered out of range.
This example shows how to configure a double-tag-to-double-tag translation of packets that are tagged with both an inner customer-edge VLAN of 109 and an outer provider-edge VLAN of 41. The translated outgoing packets have an inner customer-edge VLAN tag of 109 and an outer trunk VLAN tag of 203.
Router# configure terminal Router(config)# interface GE-WAN 4/1.203 Router(config-subif)# encapsulation dot1q 203 Router(config-subif)# bridge-vlan 41 dot1q-tunnel 109 Router(config-subif)#
NoteThe above configuration also associates the block of 32 customer-edge VLANs ranging from 96 to 127 with provider-edge VLAN 41. All other customer-edge VLAN IDs are considered out of range.
This example shows how to configure a double-tag-to-double-tag translation of out-of-range packets. If this configuration is given together with the configuration shown above, this subinterface matches packets with an outer provider-edge VLAN of 41 and an inner customer-edge VLAN that is either missing, or that is in the range from 0 to 95 or from 128 to 4094. The translated outgoing packets keep the original out-of-range customer-edge VLAN as the inner VLAN and an outer trunk VLAN tag of 981.
Router# configure terminal Router(config)# interface GE-WAN 4/1.1001 Router(config-subif)# encapsulation dot1q 981 Router(config-subif)# bridge-vlan 41 dot1q-tunnel out-range Router(config-subif)#This example shows the error message that appears when you attempt to specify the out-range keyword for a provider-edge VLAN before configuring at least one subinterface with a specific customer-edge VLAN ID for that same provider-edge VLAN:
Router# configure terminal Router(config)# interface GE-WAN 4/1.1001 Router(config-subif)# bridge-vlan 2 dot1q-tunnel out-range % bridge-vlan 2 does not have any inner-vlan configured. out-of-range configuration needs at least one inner-vlan defined to determine the range. Router(config-subif)#This example shows the system message that appears when you attempt to specify a VLAN ID that is already being used. In most cases, this message means that you have previously used this VLAN ID in another configuration or that the router has assigned this ID to an internal VLAN:
Router# configure terminal Router(config)# interface GE-WAN 4/1.234 Router(config-subif)# bridge-vlan 123 dot1q 234 Command rejected: VLAN 123 not available Router(config-subif)#
Tip
To display a list of the internal VLANs that are currently in use on the router, use the showvlaninternalusage command.
Related Commands
Command
Description
class-map
Accesses the QoS class-map configuration mode to configure QoS class maps.
encapsulation dot1q
Specifies the trunk VLAN to use on outgoing packets.
mode dot1q-in-dot1q access-gateway
Enables a Gigabit Ethernet WAN interface to act as a gateway for QinQ VLAN translation.
policy-map
Accesses QoS policy-map configuration mode to configure the QoS policy map.
service-policy
Attaches a policy map to an interface.
set cos cos-inner (policy-map configuration)
Sets the 802.1Q prioritization bits in the trunk VLAN tag of a QinQ-translated outgoing packet.
show cwan qinq
Displays the inner, outer, and trunk VLANs that are used in QinQ translation.
show cwan qinq bridge-domain
Displays the provider-edge VLAN IDs that are used on a Gigabit Ethernet WAN interface for QinQ translation or to show the customer-edge VLANs that are used for a specific provider-edge VLAN.
show cwan qinq interface
Displays interface statistics for IEEE 802.1Q-in-802.1Q (QinQ) translation on one or all Gigabit Ethernet WAN interfaces and port-channel interfaces.
show vlan internal usage
Displays a list of the internal VLANs that are currently in use on the router.
clear gvrp statistics
To clear Generic VLAN Registration Protocol (GVRP)-related statistics recorded on one or all GVRP enabled ports, use the cleargvrpstatisticscommand in privileged EXEC mode.
clear mac-address-table
To remove a specified address (or set of addresses) from the MAC address table, use the clearmac-address-tablecommand inprivileged EXEC mode.
Using Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers
clear mac-address-table [ dynamic | restricted static | permanent ] [ address mac-address ] [ interface type module port ]
clear mac-address-table notification mac-move counter [vlan]
clear mac-address-table dynamic [ address mac-address | interface interface-type interface-number | vlan vlan-id ]
clear mac-address-table [ address mac-address | interface interface-type interface-number | bridge-domain bridge-domain-id ]
Syntax Description
dynamic
(Optional) Clears only dynamic addresses.
secure
(Optional) Clears only secure addresses.
static
(Optional) Clears only static addresses.
restricted static
(Optional) Clears only restricted static addresses.
permanent
(Optional) Clears only permanent addresses.
address
(Optional) Clears only a specified address.
mac -address
(Optional) Specifies the MAC address.
interface
(Optional) Clears all addresses for an interface.
type
(Optional) Interface type: ethernet, fastethernet, fddi, atm, or port channel.
slot
(Optional) The module interface number.
interface-type interface-number
(Optional) Module and port number. The see the “Usage Guidelines” section for valid values.
notification mac-move counter
Clears the MAC-move notification counters.
vlan
(Optional) Specifies the VLAN to clear the MAC-move notification counters.
protocol assigned
(Optional) Specifies the assigned protocol accounts for such protocols such as DECnet, Banyan VINES, and AppleTalk.
protocol ip | ipx
(Optional) Specifies the protocol type of the entries to clear.
protocol other
(Optional) Specifies the protocol types (other than IP or IPX) of the entries to clear.
vlan vlan-id
(Optional) Specifies the VLAN ID; valid values are from 1 to 4094.
module
(Optional) The module interface number:
port
(Optional)
Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers:
Port interface number ranges based on type of Ethernet switch network module used:
Catalyst Switches
Port interface number ranging from 1 to 28:
bridge-domain bridge-domain-id
(Optional) Specifies the bridge-domain ID; valid values are from 1 to 16384.
Command Default
Using Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers
All MAC addresses on the router being configured are cleared.
Using Catalyst Switches
The dynamic addresses are cleared.
Clearing a Dynamic Address
This command has no defaults in this mode.
Command History
Release
Modification
12.2(2)XT
This command was introduced 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.
12.2(14)SX
Support for this command was introduced on the Supervisor Engine 720.
12.2(17d)SXB
Support for this command on the Supervisor Engine 2 was extended to Cisco IOS Release 12.2(17d)SXB.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(33)SXI
This command was changed to add the notificationmac-movecounter [vlan] keywords and argument.
15.2(02)SA
This command was implemented on the Cisco ME 2600X Series Ethernet Access Switches.
Usage Guidelines
Using Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers
If the clearmac-address-table command is invoked with no options, all MAC addresses are removed. If you specify an address but do not specify an interface, the address is deleted from all interfaces. If you specify an interface but do not specify an address, all addresses on the specified interface are removed.
Using Catalyst Switches
If the clearmac-address-table command is invoked with no options, all dynamic addresses are removed. If you specify an address but do not specify an interface, the address is deleted from all interfaces. If you specify an interface but do not specify an address, all addresses on the specified interface are removed.
If a targeted address is not present in the MAC forwarding table, the following error message appears:
MAC address not foundClearing a Dynamic Address
The valid values for the interface argument include thege-wan, atm, and pos keywords that are supported on Cisco 7600 series routers that are configured with a Supervisor Engine 2.
The protocol {assigned | ip | ipx| other} keywords are supported on Cisco 7600 series routers that are configured with a Supervisor Engine 2 only.
Enter the clearmac-address-tabledynamic command to remove all dynamic entries from the table.
The following values are valid for interface-type:
Setting the Module and Port
The interface-number argument designates the module and port number. Valid values for interface-number depend on the specified interface type and the chassis and module that are used. For example, if you specify a Gigabit Ethernet interface and have a 48-port 10/100BASE-T Ethernet module that is installed in a 13-slot chassis, valid values for the module number are from 1 to 13 and valid values for the port number are from 1 to 48.
Examples
Using Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers
The following example shows how to clear all dynamic addresses in the MAC forwarding table:
Router# clear mac-address-table dynamicThe following example shows how to clear the static address 0040.C80A.2F07 on Ethernet port 1:
Router# clear mac-address-table static address 0040.C80A.2F07 interface ethernet 0/1Using Catalyst Switches
The following example shows how to clear all dynamic addresses in the MAC forwarding table:
Router# clear mac-address-table dynamicThe following example shows how to clear the MAC-move notification counters on a specific VLAN:
Router# clear mac-address-table notification mac-move counter 202The following example shows the permanent address 0040.C80A.2F07 being cleared on Ethernet port 1:
Router# clear mac-address-table permanent address 0040.C80A.2F07 interface ethernet 0/1Clearing a Dynamic Address on a 7600 using a Supervisor Engine 2
This example shows how to clear all dynamic Layer 2 entries for a specific interface (abc) and protocol type (IPX):
Router# clear mac-address-table dynamic interface abc protocol ipxRelated Commands
Command
Description
mac -address-tableaging-time
Configures the length of time the switch keeps dynamic MAC addresses in memory before discarding.
mac -address-tablepermanent
Associates a permanent unicast or multicast MAC address with a particular switched port interface.
mac -address-tablerestrictedstatic
Associates a restricted static address with a particular switched port interface.
mac -address-tablesecure
Associates a secure static address with a particular switched port interface.
mac-address-table static
Adds static entries to the MAC-address table or configures a static MAC address with IGMP snooping disabled for that address.
show mac -address-table
Displays addresses in the MAC address table for a switched port or module.
show mac -address-tablesecure
Displays the addressing security configuration.
show mac -address-tablesecurity
Displays the addressing security configuration.
clear mvr counters
To clear the join counters of all the Multicast VLAN Registration (MVR) ports, source ports, receiver ports, or of a specific MVR interface port, use the clear mvr counters command in privileged EXEC mode.
Syntax Description
receiver-ports
Configures a port as a receiver port if it is a subscriber port. As a receiver port, it should only receive multicast data.
source-ports
Configures uplink ports that receive and send multicast data as source ports.
type
(Optional) Specifies the Interface type.
module/port
(Optional) Specifies the module or port number.
Examples
This example shows how to clear the join counters for the receiver port on the GigabitEthernet port 1/7.
Router# clear mvr receiver-ports GigabitEthernet 1/7 Router# show mvr receiver-ports GigabitEthernet 1/7 Joins: v1,v2,v3 counter shows total IGMP joins v3 counter shows IGMP joins received with both MVR and non-MVR groups Port VLAN Status Immediate Joins Leave (v1,v2,v3) (v3) ---- ---- ------------- ---------- ---------- ----------- Gi1/7 202 INACTIVE/UP ENABLED 0 0Related Commands
Command
Description
mvr
Enables Multicast VLAN Registration (MVR) on the router.
mvr group
Configures an MVR group on the router.
mvr max–groups
Configures the maximum number of MVR groups on the router.
mvr querytime
Configures the MVR query response time.
mvr vlan
Configures the VLAN in which the multicast data is received.
mvr type
Configures a switch port as an MVR receiver or source port.
mvr immediate
Enables the immediate leave feature of the MVR on the port.
show mvr
Displays the MVR details.
show mvr groups
Displays the MVR group configuration.
show mvr interface
Displays details of all the MVR member interfaces or a single requested MVR member interface.
show mvr members
Displays details of all the MVR members and number of MVR members in all active MVR groups on a particular VLAN or port.
show mvr receiver-ports
Displays all receiver ports that are members of an IP multicast group or those on the specified interface port.
show mvr source–ports
Displays all source ports that are members of an IP multicast group or those on the specified interface port.
clear mvrp statistics
To clear statistics related to Multiple VLAN Registration Protocol (MVRP) and recorded on one (or all) MVRP-enabled ports, use the clearmvrpstatistics command in privileged EXEC configuration mode.
Usage Guidelines
Use this command to clear collected statistics for MVRP-enabled devices or interfaces. If used without the interface keyword, the command clears all MVRP statistics on the device.
clear pagp
clear spanning-tree detected-protocol
To restart the protocol migration process, use the clearspanning-treedetected-protocol command in privileged EXEC mode.
clear spanning-tree detected-protocol [ interface [ interface-type interface-number ] | port-channel pc-number | vlan vlan-interface ]
Syntax Description
interface
(Optional) Specifies the interface
interface-type
The type of interface that you want to clear the detected spanning tree protocol for.
interface-number
The of the interface that you want to clear the detected spanning tree protocol for.
port-channel
Clears the detected spanning tree protocol for a port-channel.
pc-number
Specifies the port channel interface. Range: 1 to 282.
vlan
Clears the detected spanning tree protocol for a VLAN.
vlan-interface
Specifies the VLAN interface. Range: 1 to 4094.
Usage Guidelines
RSTP and MST have built-in compatibility mechanisms that allow them to interact properly with other versions of IEEE spanning tree or other regions. For example, a bridge running RSTP can send 802.1D BPDUs on one of its ports when it is connected to a legacy bridge. An MST bridge can detect that a port is at the boundary of a region when it receives a legacy BPDU or an MST BPDU that is associated with a different region. These mechanisms are not always able to revert to the most efficient mode. For example, an RSTP bridge that is designated for a legacy 802.1D stays in 802.1D mode even after the legacy bridge has been removed from the link. Similarly, an MST port assumes that it is a boundary port when the bridges to which it is connected have joined the same region. To force the MST port to renegotiate with the neighbors, enter the clearspanning-treedetected-protocol command.
If you enter the clearspanning-treedetected-protocol command with no arguments, the command is applied to every port of the Cisco 7600 series router.
clear vlan
To delete an existing VLAN from a management domain, use the clearvlan command in privileged EXEC mode.
Command History
Release
Modification
12.0
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
Usage Guidelines
Follow these guidelines for deleting VLANs:
- When you delete an Ethernet VLAN in Virtual Trunking Protocol (VTP) server mode, the VLAN is removed from all switches in the same VTP domain.
- When you delete a VLAN in VTP transparent mode, the VLAN is deleted only on the current switch.
- To delete a Token Ring Bridge Relay Function (TRBRF) VLAN, you must either first reassign its child Token Ring Concentrator Relay Functions (TRCRFs) to another parent TRBRF or delete the child TRCRFs.
Caution
When you clear a VLAN, all ports assigned to that VLAN become inactive. However, the VLAN port assignments are retained until you move the ports to another VLAN. If the cleared VLAN is reactivated, all ports still configured on that VLAN are also reactivated. A warning is displayed if you clear a VLAN that exists in the mapping table.
clear vlan counters
To clear the software-cached counter values to start from zero again for a specified VLAN or all existing VLANs, use the clearvlancounters command in privileged EXEC mode.
Usage Guidelines
If you do not specify a vlan-id; the software-cached counter values for all existing VLANs are cleared.
clear vlan mapping
To delete existing 802.1Q virtual LAN (VLAN) to Inter-Switch Link (ISL) VLAN-mapped pairs, use the clearvlanmapping command in privileged EXEC mode.
Command History
Release
Modification
12.0
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
Examples
The following example shows how to clear an existing mapped 802.1Q VLAN (VLAN 1044) from the mapping table:
Router# clear vlan mapping dot1q 1044 Vlan Mapping 1044 Deleted.The following example shows how to clear all mapped 802.1Q VLANs from the mapping table:
Router# clear vlan mapping dot1q all All Vlan Mapping Deleted.clear vlan statistics
To remove virtual LAN (VLAN) statistics from any statically or system-configured entries, use the clearvlanstatistics command in privileged EXEC mode.
Command History
Release
Modification
11.2
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
clear vtp counters
To clear VLAN Trunk Protocol (VTP) counters, use the clearvtpcounters command in privileged EXEC mode.
Command History
Release
Modification
15.0(1)M
This command was introduced in a release earlier than Cisco IOS Release 15.0(1)M.
12.2(33)SRE
This command was integrated into a release earlier than Cisco IOS Release 12.2(33)SRE.
12.2(33)SXI
This command was integrated into a release earlier than Cisco IOS Release 12.2(33)SXI.
collect top counters interface
To list the TopN processes and specific TopN reports, use the collecttopcountersinterface command in user EXEC or privileged EXEC mode.
collect top [number] counters interface interface-type [ interval seconds ] [ sort-by sort-by-value ]
Syntax Description
number
(Optional) Number of ports to be displayed; valid values are from 1 to 5000 physical ports. The default is 20 physical ports.
interface-type
Type of ports to be used in the TopN request; valid values are all, ethernet, fastethernet, gigabitethernet, tengigabitethernet, layer-2vlan-num, and layer-3. The default is all.
The layer-2vlan-num keyword and argument represents the number of Layer 2 interfaces. Range:1 to 4094.
interval seconds
(Optional) Specifies the interval over which the statistics are gathered. Range: 0 to 999 seconds. The default is 30 seconds.
sort-by sort-by-value
Specifies the port statistic to generate the report on; valid values are as follows:
- broadcast --Sorts the report based on the receive and transmit broadcast packets.
- bytes --Sorts the report based on the receive and transmit bytes.
- errors --Sorts the report based on the receive errors.
- multicast --Sorts the report based on the receive and transmit multicast packets.
- overflow --Sorts the report based on the transmit overflow errors.
- packets --Sorts the report based on the receive and transmit packets.
- utilization --Sorts the report based on the port utilization. This is the default.
Command Default
The defaults are as follows:
- number is 20 physical ports.
- interface-type is all
- seconds is 30 seconds.
- sort-by-value is utilization
Usage Guidelines
This command is supported on Ethernet, Fast Ethernet, Gigabit Ethernet, and 10-Gigabit Ethernet ports only. LAN ports on the OSMs are also supported.
If you specify an interval of 0 seconds, the TopN report is generated based on the absolute counters value.
Specifying the intervalseconds keyword and the sort-by-valueargument when the sorting criteria is utilization will not return a valid report because utilization can only be computed over an interval. For example, this syntax-collecttopcountersinterfacefastEthernetsort-byutilizationinterval45, will not generate a valid report.
Only a TopN task with a done status is allowed to display the report. If you try to view a report that is incomplete (pending), an appropriate message is displayed.
The TopN utility collects the following port utilization data for each physical port over the secondsinterval:
- Total number of in and out bytes
- Total number of in and out packets
- Total number of in and out broadcast packets
- Total number of in and out multicast packets
- Total number of in errors (Ethernet ports such as CRC, undersize packets (+Runt), oversize packets, fragmentation, and jabber)
- Total number of buffer-overflow errors (including outlost packets; for example, transmit errors that are due to the buffer full and Ethernet ports: dmaTxOverflow and dmaTxFull)
After the collection of information, the ports are sorted according to the sort-by-value argument, and the top number of ports are displayed.
When the TopN reports are ready, a syslog message is displayed that the TopN reports are available. You can use the showtopinterfacereport command to view the reports. You can display the TopN reports multiple times until you enter the cleartopinterfacereport command to clear the reports.
Use the cleartopinterfacereport command to clear the reports.
Examples
This example shows how to sort the TopN report based on the receive and transmit broadcast packets:
Router# collect top 40 counters interface all sort-by broadcastThis example shows how to sort the TopN report based on the receive and transmit broadcast packets and specify the TopN sampling interval:
Router# collect top 40 counters interface all interval 500 sort-by broadcastdebug udld
To enable the debugging of UniDirectional Link Detection (UDLD) protocol, use the debug udld command in the privileged EXEC mode. To disable the debugging output, use the no form of this command.
Syntax Description
events
Enables debugging of UDLD process events as they occur.
packets
Enables debugging of the UDLD process as it receives packets from the packet queue and attempts to transmit packets at the request of the UDLD protocol code.
registries
Enables debugging of the UDLD process as it processes the registry upcalls from the UDLD process-dependent module and the other feature modules.
Usage Guidelines
The debug udld command is used to debug UDLD in case of any errors. The debug logs are used to analyze the error and find out where exactly the problem is occurring in UDLD.
Examples
The following is sample output from the debug udld events command:
Router# debug udld events UDLD events debugging is onThe following is sample output from the debug udld packets command:
Router# debug udld packets UDLD packets debugging is onThe following is sample output from the debug udld registries command:
Router# debug udld registries UDLD registries debugging is onRelated Commands
Command
Description
show udld
Displays the administrative and operational UDLD statuses.
udld
Enables the aggressive mode or the normal mode in UDLD and sets the configurable message time.
udld port
Enables UDLD on the Ethernet interface or enables UDLD in the aggressive mode on the Ethernet interface.
udld recovery
Enables the recovery timer for the UDLD error-disabled state.
udld reset
Resets all the LAN ports that are error disabled by UDLD.
dot1q tunneling ethertype
To define the Ethertype field type used by peer devices when implementing Q-in-Q VLAN tagging, use the dot1qtunnelingethertypecommand in interface configuration mode. To remove the VLAN tag Ethertype, use the no form of this command.
Command Default
The Ethertype field used by peer devices when implementing Q-in-Q VLAN tagging is 0x8100.
Command History
Release
Modification
12.3(7)T
This command was introduced.
12.3(7)XI1
This command was implemented on the Cisco 10000 series routers.
12.2(31)SB2
This command was integrated into Cisco IOS Release 12.2(31)SB2.
12.2(33)SRC
This command was integrated into Cisco IOS Release 12.2(33)SRC.
Cisco IOS XE Release 2.2
This command was integrated into Cisco IOS XE Release 2.2.
Usage Guidelines
Use the dot1qtunnelingethertype command if the peer switching devices are using an Ethertype field value of 0x9100 or 0x9200. All Cisco switching devices use the default Ethertype field value of 0x88A8. The Cisco 10000 series router also supports the 0x9200 Ethertype field value.
NoteOn the Cisco 10000 series router, the Ethertype field for the outer VLAN ID can be changed, but the Ethertype field for the inner VLAN ID cannot be changed.
This command is used with the IEEE 802.1Q-in-Q VLAN Tag Termination feature in which double VLAN tagging is configured using the encapsulationdot1q command. 802.1Q double tagging allows a service provider to use a single VLAN to support customers who have multiple VLANs.
Examples
The following example shows how to configure an Ethertype field as 0x9100:
Router(config ) # interface gigabitethernet 1/0/0 Router(config -if)# dot1q tunneling ethertype 0x9100The following example shows how to configure an Ethertype field as 0x9200 on a Cisco 10000 series router:
Router(config)# interface gigabitethernet 1/0/0 Router(config-if)# dot1q tunneling ethertype 0x9200encapsulation dot1q
To enable IEEE 802.1Q encapsulation of traffic on a specified subinterface in a VLAN, use the encapsulationdot1q command in interface range configuration mode or subinterface configuration mode. To disable IEEE 802.1Q encapsulation, use the no form of this command.
Interface Range Configuration Mode
encapsulation dot1q vlan-id second-dot1q { any | vlan-id } [native]
no encapsulation dot1q
Subinterface Configuration Mode
encapsulation dot1q vlan-id second-dot1q { any | vlan-id | vlan-id-vlan-id | [ ,vlan-id-vlan-id ] }
no encapsulation dot1q vlan-id second-dot1q { any | vlan-id | vlan-id-vlan-id | [ ,vlan-id-vlan-id ] }
Syntax Description
vlan-id
Virtual LAN identifier. The allowed range is from 1 to 4094. For the IEEE 802.1Q-in-Q VLAN Tag Termination feature, the first instance of this argument defines the outer VLAN ID, and the second and subsequent instances define the inner VLAN ID.
native
(Optional) Sets the VLAN ID value of the port to the value specified by the vlan-id argument.
Note This keyword is not supported by the IEEE 802.1Q-in-Q VLAN Tag Termination feature.
second-dot1q
Supports the IEEE 802.1Q-in-Q VLAN Tag Termination feature by allowing an inner VLAN ID to be configured.
any
Sets the inner VLAN ID value to a number that is not configured on any other subinterface.
Note The any keyword in the second-dot1qcommand is not supported on a subinterface configured for IP over Q-in-Q (IPoQ-in-Q) because IP routing is not supported on ambiguous subinterfaces.
-
Separates the inner and outer VLAN ID values in the range to be defined. The hyphen is required.
,
Separates each VLAN ID range from the next range. The comma is required. Do not insert spaces between the values.
Command Modes
Interface range configuration (config-int-range) Subinterface configuration (config-ifsub)
Command History
Release
Modification
12.0(1)T
This command was introduced.
12.1(3)T
The native keyword was added.
12.2(2)DD
Support was added for this command in interface range configuration mode.
12.2(4)B
This command was integrated into Cisco IOS Release 12.2(4)B.
12.2(8)T
This command was integrated into Cisco IOS Release 12.2(8)T.
12.3(7)T
The second-dot1q keyword was added to support the IEEE 802.1Q-in-Q VLAN Tag Termination feature.
12.3(7)XI1
This command was integrated into Cisco IOS Release 12.3(7)XI and implemented on the Cisco 10000 series routers.
12.2(28)SB
This command was integrated into Cisco IOS Release 12.2(28)SB.
12.2(31)SB2
This command was integrated into Cisco IOS Release 12.2(31)SB2.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
12.2(33)SRC
This command was integrated into Cisco IOS Release 12.2(33)SRC.
Cisco IOS XE Release 2.2
This command was integrated into Cisco IOS XE Release 2.2.
15.2(02)SA
This command was implemented on the Cisco ME 2600X Series Ethernet Access Switches.
Usage Guidelines
Interface Range Configuration Mode
IEEE 802.1Q encapsulation is configurable on Fast Ethernet interfaces. IEEE 802.1Q is a standard protocol for interconnecting multiple switches and routers and for defining VLAN topologies.
Use the encapsulationdot1qcommand in interface range configuration mode to apply a VLAN ID to each subinterface within the range specified by theinterfacerange command. The VLAN ID specified by the vlan-id argument is applied to the first subinterface in the range. Each subsequent interface is assigned a VLAN ID, which is the specified vlan-id value plus the subinterface number minus the first subinterface number (VLAN ID + subinterface number - first subinterface number).
NoteThe Cisco 10000 series router does not support the interfacerange command nor the interface range configuration mode.
Do not configure encapsulation on the native VLAN of an IEEE 802.1Q trunk without using the native keyword. (Always use the native keyword when vlan-id is the ID of the IEEE 802.1Q native VLAN.)
Subinterface Configuration Mode
Use the second-dot1q keyword to configure the IEEE 802.1Q-in-Q VLAN Tag Termination feature. 802.1Q in 802.1Q (Q-in-Q) VLAN tag termination adds another layer of 802.1Q tag (called “metro tag” or “PE-VLAN”) to the 802.1Q tagged packets that enter the network. Double tagging expands the VLAN space, allowing service providers to offer certain services such as Internet access on specific VLANs for some customers and other types of services on other VLANs for other customers.
After a subinterface is defined, use the encapsulationdot1qcommand to add outer and inner VLAN ID tags to allow one VLAN to support multiple VLANs. You can assign a specific inner VLAN ID to the subinterface; that subinterface is unambiguous. Or you can assign a range or ranges of inner VLAN IDs to the subinterface; that subinterface is ambiguous.
Examples
The following example shows how to create the subinterfaces within the range 0.11 and 0.60 and apply VLAN ID 101 to the Fast Ethernet0/0.11 subinterface, VLAN ID 102 to Fast Ethernet0/0.12 (vlan-id= 101 + 12 - 11 = 102), and so on up to VLAN ID 150 to Fast Ethernet0/0.60 (vlan-id= 101 + 60 - 11 = 150):
Router(config)# interface range fastethernet0/0.11 - fastethernet0/0.60 Router(config-int-range)# encapsulation dot1q 101The following example shows how to terminate a Q-in-Q frame on an unambiguous subinterface with an outer VLAN ID of 100 and an inner VLAN ID of 200:
Router(config)# interface gigabitethernet1/0/0.1 Router(config-subif)# encapsulation dot1q 100 second-dot1q 200The following example shows how to terminate a Q-in-Q frame on an ambiguous subinterface with an outer VLAN ID of 100 and an inner VLAN ID in the range from 100 to 199 or from 201 to 600:
Router(config)# interface gigabitethernet1/0/0.1 Router(config-subif)# encapsulation dot1q 100 second-dot1q 100-199,201-600Related Commands
Command
Description
encapsulation isl
Enables the ISL, which is a Cisco proprietary protocol for interconnecting multiple switches and maintaining VLAN information as traffic goes between switches.
encapsulation sde
Enables IEEE 802.10 encapsulation of traffic on a specified subinterface in VLANs.
interface range
Specifies multiple subinterfaces on which subsequent commands are executed at the same time.
show vlans dot1q
Displays information about 802.1Q VLAN subinterfaces.
encapsulation isl
To enable the Inter-Switch Link (ISL), use the encapsulationisl command in subinterface configuration mode. To disable the ISL, use the no form of this command.
Usage Guidelines
ISL is a Cisco protocol for interconnecting multiple switches and routers, and for defining VLAN topologies.
ISL encapsulation is configurable on Fast Ethernet interfaces.
ISL encapsulation adds a 26-byte header to the beginning of the Ethernet frame. The header contains a 10-bit VLAN identifier that conveys VLAN membership identities between switches.
To enter the subinterface configuration mode, you must enter the interface configuration mode first and then enter the interface command to specify a subinterface.
encapsulation sde
To enable IEEE 802.10 encapsulation of traffic on a specified subinterface in virtual LANs (VLANs), use the encapsulationsde command in subinterface configuration mode. To disable IEEE 802.10 encapsulation, use the no form of this command.
Command History
Release
Modification
10.3
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
Usage Guidelines
IEEE 802.10 is a standard protocol for interconnecting multiple switches and routers and for defining VLAN topologies.
Secure Data Exchange (SDE) encapsulation is configurable only on the following interface types:
- IEEE 802.10 routing: FDDI
flowcontrol
To configure a port to send or receive pause frames, use the flowcontrol command in interface configuration mode. To return to the default settings, use the no form of this command.
flowcontrol { send | receive } { desired | off | on }
no flowcontrol { send | receive } { desired | off | on }
Syntax Description
send
Specifies that a port sends pause frames.
receive
Specifies that a port processes pause frames.
desired
Obtains predictable results regardless of whether a remote port is set to on, off, or desired.
off
Prevents a local port from receiving and processing pause frames from remote ports or from sending pause frames to remote ports.
on
Enables a local port to receive and process pause frames from remote ports or send pause frames to remote ports.
Command Default
Flow control is disabled.
Flow-control defaults depend upon port speed. The defaults are as follows:
- Gigabit Ethernet ports default to off for receive and desired for send.
- Fast Ethernet ports default to off for receive and on for send.
- On the 24-port 100BASE-FX and 48-port 10/100 BASE-TX RJ-45 modules, the default is off for receive and off for send.
- You cannot configure how WS-X6502-10GE 10-Gigabit Ethernet ports respond to pause frames. WS-X6502-10GE 10-Gigabit Ethernet ports are permanently configured to respond to pause frames.
Command History
Release
Modification
12.2(14)SX
This command was introduced on the Supervisor Engine 720.
12.2(17d)SXB
This command was implemented on the Supervisor Engine 2.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(33)SCB
This command was integrated into Cisco IOS Release 12.2(33)SCB.
Usage Guidelines
The send and desired keywords are supported on Gigabit Ethernet ports only.
Pause frames are special packets that signal a source to stop sending frames for a specific period of time because the buffers are full.
Gigabit Ethernet ports on the Catalyst 6500 series switches and on the Cisco 7600 series routers use flow control to inhibit the transmission of packets to the port for a period of time; other Ethernet ports use flow control to respond to flow-control requests.
If a Gigabit Ethernet port receive buffer becomes full, the port transmits a “pause” packet that tells remote ports to delay sending more packets for a specified period of time. All Ethernet ports (1000 Mbps, 100 Mbps, and 10 Mbps) can receive and act upon “pause” packets from other devices.
You can configure non-Gigabit Ethernet ports to ignore received pause frames (disable) or to react to them (enable).
When used with the receivekeyword, the on and desired keywords have the same result.
All the Gigabit Ethernet ports on the Catalyst 6500 series switches and the Cisco 7600 series routers can receive and process pause frames from remote devices.
To obtain predictable results, follow these guidelines:
- Use sendon only when remote ports are set to receiveon or receivedesired.
- Use sendoff only when remote ports are set to receiveoff or receivedesired.
- Use receiveon only when remote ports are set to sendon or senddesired.
- Use sendoff only when remote ports are set to receiveoff or receivedesired.
Examples
These examples show how to configure the local port to not support any level of flow control by the remote port:
Router# configure terminal Router(config)# interface GigabitEthernet1/9 10.4.9.157 255.255.255.0 Router(config-if)# flowcontrol receive off Router(config-if)# flowcontrol send offflowcontrol (line)
To set the method of data flow control between the terminal or other serial device and the router, use the flowcontrol command in line configuration mode. To disable flow control, use the no form of this command.
flowcontrol { none | software [lock] [ in | out ] | hardware [ in | out ] }
no flowcontrol { none | software [lock] [ in | out ] | hardware [ in | out ] }
Syntax Description
none
Turns off flow control.
software
Sets software flow control.
lock
(Optional) Makes it impossible to turn off flow control from the remote host when the connected device needs software flow control. This option applies to connections using the Telnet or rlogin protocols.
in | out
(Optional) Specifies the direction of software or hardware flow control: the keyword in c auses the Cisco IOS software to listen to flow control from the attached device, and the outkeywordc auses the software to send flow control information to the attached device. If you do not specify a direction, both directions are assumed.
hardware
Sets hardware flow control. For more information about hardware flow control, see the hardware manual that was shipped with your router.
Usage Guidelines
When software flow control is set, the default stop and start characters are Ctrl-S and Ctrl-Q (XOFF and XON). You can change them using the stop-character and start-character commands.
If a remote Telnet device requires software flow control, the remote system should not be able to turn it off. Using the lock option makes it possible to refuse “dangerous” Telnet negotiations if they are inappropriate.
flowcontrol receive
To temporarily stop the transmission of data between two peers to prevent packet drops in the event of data overflow , use the flowcontrolreceive command in interface configuration mode. To return to the default settings, use the no form of this command.
gvrp global
To enable Generic VLAN Registration Protocol (GVRP) globally on a device and on an interface, use the gvrpglobalcommand in global configuration mode. To disable GRVP, use the no form of this command.
Command Default
GVRP is administratively disabled.
GRVP is administratively enabled on each interface.
Usage Guidelines
GVRP is operational on an interface only if GVRP is administratively enabled globally at the device level and at the interface level.
When GVRP is operational on an interface, GVRP protocol data units (PDUs) are transmitted out the interface which must be a forwarding IEEE 802.1Q trunk port.
Examples
The following example configures global GVRP on the device and interfaces:
Router(config)# gvrp globalRelated Commands
Command
Description
clear gvrp statistics
Clears GVRP related statistics recorded on one or all GVRP enabled ports.
debug gvrp
Displays GVRP debugging information.
gvrp mac-learning auto
Enables GVRP to provision MAC address learning.
gvrp registration
Sets the registrars in a GID instance associated with an interface.
gvrp timer
Sets period timers that are used in GARP on a given interface.
gvrp vlan create
Enables a GVRP dynamic VLAN.
show gvrp summary
Displays the GVRP configuration at the device level.
show gvrp interface
Displays details of the administrative and operational GVRP states of all or one particular IEEE 802.1Q trunk port in the device.
gvrp mac-learning auto
To disable MAC learning, use the gvrpmac-learningcommand in global configuration mode. To enable learning of dynamic mac-entries, use the no form of this command.
Usage Guidelines
Disables MAC learning on VLANs that are configured with Compact Generic Attribute Registration Protocol (GARP) VLAN Registration Protocol (GVRP) (cGVRP).
Related Commands
Command
Description
clear gvrp statistics
Clears GVRP-related statistics recorded on one or all GVRP enabled ports.
debug gvrp
Displays GVRP debugging information.
gvrp global
Enables GVRP globallly on a device and on a particular interface.
gvrp registration
Sets the registrars in a GID instance associated with an interface.
gvrp timer
Sets period timers that are used in GARP on a given interface.
gvrp vlan create
Enables a GVRP dynamic VLAN.
show gvrp summary
Displays the GVRP configuration at the device level.
show gvrp interface
Displays details of the administrative and operational GVRP states of all or one particular .1Q trunk port in the device.
gvrp registration
Toset the registrars in a global information distribution (GID) instance associated with an interface, use the gvrpregistrationcommand in global configuration mode. To disable the registrars, use the no form of this command.
Usage Guidelines
The gvrpregistration command is only operational if GVRP is configured on an interface.
The nogvrpregistration command sets the registrar state to the default.
The maximum number of Registrars is 4094.
Examples
The following example sets a fixed, forbidden, and normal registrar on a GID instance:
gvrp global ! int g6/1 gvrp registration fixed ! int g6/2 gvrp registration forbidden ! int g6/3 no gvrp registrationRelated Commands
Command
Description
clear gvrp statistics
Clears GVRP related statistics recorded on one or all GVRP enabled ports.
debug gvrp
Displays GVRP debugging information.
gvrp global
Enables GVRP globally on a device and on a particular interface.
gvrp mac-learning auto
Disables MAC learning.
gvrp timer
Sets period timers that are used in GARP on a given interface.
gvrp vlan create
Enables a GVRP dynamic VLAN.
show gvrp summary
Displays the GVRP configuration at the device leve.
show gvrp interface
Displays details of the adininstrative and operational GVRP states of all or one particular .1Q trunk port in the device.
gvrp timer
To set period timers that are used in General Attribute Registration Protocol (GARP) on an interface, use the gvrptimercommand in interface configuration mode. To remove the timer value, use the no form of this command.
Syntax Description
join
Time interval between two transmit PDUs.
leave
Time before a Registrar is moved to MT from LV.
leave-all
Time it takes for a LeaveAll timer to expire.
timer-value
Value in milliseconds for the associated keyword. Valid entries are as follows:
- Join timer value range is 200 to 100000000
- Leave timer value range is 600 to 100000000
- LeaveAll timer value range is 10000 to 100000000
Command Default
Join timer value default is 200 milliseconds.
Leave timer value default is 600 milliseconds.
LeaveAll time value default is 10000 milliseconds.
Examples
The following example sets timer levels on an interface:
gvrp global ! int g6/1 ! gvrp timer join 1000 ! gvrp timer leave 1200 ! no gvrp timer leaveallRelated Commands
Command
Description
clear gvrp statistics
Clears GVRP related statistics recorded on one or all GVRP enabled ports.
debug gvrp
Displays GVRP debugging information.
gvrp global
Enables GVRP globallly on a device and on a particular interface.
gvrp mac-learning auto
Disables MAC learning.
gvrp registration
Sets the registrars in a GID instance associated with an interface.
gvrp vlan create
Enables a GVRP dynamic VLAN.
show gvrp summary
Displays the GVRP configuration at the device level.
show gvrp interface
Displays details of the adininstrative and operational GVRP states of all or one particular .1Q trunk port in the device.
gvrp vlan create
To enable a Generic VLAN Registration Protocol (GVRP) on a device, use the gvrpvlancreatecommand in global configuration mode. To disable a dynamic VLAN, use the no form of this command.
Usage Guidelines
VLAN Trunk Protocol (VTP) must be in transparent mode in order to configure a GVRP dynamic VLAN.
Examples
The following example configures a GVRP dynamic VLAN:
vtp mode transparent ! gvrp vlan createRelated Commands
Command
Description
clear gvrp statistics
Clears GVRP related statistics recorded on one or all GVRP enabled ports.
debug gvrp
Displays GVRP debugging information.
gvrp global
Enables GVRP globally on a device and on a particular interface.
gvrp mac-learning auto
Enables a GRVP dynamic VLAN on a device.
gvrp registration
Sets the registrars in a GID instance associated with an interface.
gvrp timer
Sets period timers that are used in GARP on a given interface.
show gvrp summary
Displays the GVRP configuration at the device level.
show gvrp interface
Displays details of the administrative and operational GVRP states of all or one particular .1Q trunk port in the device.
hw-module slot (ASR 1000 Series)
To start, stop, reload, or enable logging for an Embedded Services Processor (ESP), Route Processor (RP), or Shared Port Adapter (SPA) Interface Processor (SIP) on a Cisco ASR 1000 Series Aggregation Services Router, use the hw-moduleslot command in privileged EXEC or global configuration or diagnostic mode.
Syntax Description
slot
Slot on which logging action is to be taken. Options are as follows:
- number --the number of the SIP slot.
- f0 --The ESP in ESP slot 0.
- f1 --The ESP in ESP slot 1
- r0 --The RP in RP slot 0.
- r1 --The RP in RP slot 1.
action
The action to take on the hardware in the specified slot. Options are as follows:
- logging onboard [disable| enable] --Disables or enables onboard logging of the hardware.
- reload --Reloads the specified hardware.
- start --Starts the hardware if it has been stopped.
- stop --Stops the hardware if it is currently active.
Command Default
The router sends and receives traffic by default, so this command is not necessary to enable any hardware on a router. Onboard logging for all of the hardware is enabled by default.
Usage Guidelines
The hw-moduleslot command does not have a no form.
To start, stop, or reload a SPA, use the hw-modulesubslotcommand.
The stop and reload options cannot be used on an active RP.
All traffic to hardware that has been set to stop using the stop option will be dropped until the hardware is reenabled by either physically removing and reinserting the hardware, or entering the start option. After the hardware is modified as appropriate or the start option is entered, the hardware has to reinitialize before it is able to send and receive traffic. Note that in some cases reinitialization can take several minutes, and that the reinitialization time required depends on the hardware and the system configuration.
When a SIP is stopped, all traffic to all SPAs in the SIP is dropped. The SPAs in the SIP can begin receiving traffic after the SIP is restarted using the start option and all SPAs and the SIP finish reinitializing.
Since this is a privileged EXEC-level command, this command setting cannot be saved to the startup configuration and therefore the command setting cannot be maintained after a system reload. If you want the hardware to stay in the stop state across system reloads, use the hw-moduleslotslotshutdown global configuration command.
The reload option can be used to reload hardware for any reason; for example, to finish a software upgrade that requires reloading of the hardware or to reload the hardware as part of a troubleshooting step.
The contents of onboard logging logs can be displayed using the showloggingonboardslot privileged EXEC and diagnostic mode commands.
Enter the showloggingonboardslotslotstatus privileged EXEC or diagnostic command to see if onboard logging is enabled or disabled for the hardware in a particular slot.
When the hw-moduleslotslotloggingonboarddisable command is entered, onboard logging for the specified hardware component is disabled but the existing logs are preserved; if you want to erase the existing logs, enter the clearloggingonboardslot command.
When the hw-moduleslot command is entered in global configuration mode (for ESP40 and SIP40 cards), you have a link option that allows you to choose among a set of backplane enhanced serializer/deserializer (SerDes) interconnect (ESI) links between ESP and a given SIP slot. The range of possible values for the link depends on the type of ESP and SIP cards. Only a combination of ESP40 and SIP40 cards can have more than two ESI links (link A and link B). All other cards have only link A. For example, a combination of ESP40 and SIP10 or ESP20 and SIP40 cards can have only one link (link A).
Examples
The following example shows how to stop the RP in RP slot 0:
Router# hw-module slot r0 stopThe following example shows how to disable the onboard logging for the RP in RP slot 0. The output of the showloggingonboardslotr0statuscommand is given both before and after onboard logging is disabled to verify that onboard logging was properly disabled.
Router# show logging onboard slot r0 status Status: Enabled Router# hw-module slot r0 logging onboard disable Router# show logging onboard slot r0 status Status: DisabledThe following example shows how to display the available link options for ESP40 and SIP40 cards:
Router(config)# hw-module slot 0 qos input link ? A ESI Link A B ESI Link Binstance (VLAN)
To map a VLAN or a group of VLANs to a multiple spanning tree (MST) instance, use the instance command in MST configuration mode. To return the VLANs to the default internal spanning tree (CIST) instance, use the no form of this command.
Command Default
No VLANs are mapped to any MST instance (all VLANs are mapped to the CIST instance).
Command History
Release
Modification
12.2(14)SX
Support for this command was introduced on the Supervisor Engine 720.
12.2(17d)SXB
Support for this command on the Supervisor Engine 2 was extended to Cisco IOS Release 12.2 (17d)SXB.
12.2(18)SXF
This command was changed as follows:
Cisco IOS XE Release XE 3.7S
This command was integrated into Cisco IOS XE Release XE 3.7S.
Usage Guidelines
The vlansvlan-range is entered as a single value or a range.
The mapping is incremental, not absolute. When you enter a range of VLANs, this range is added or removed to the existing instances.
Any unmapped VLAN is mapped to the CIST instance.
Examples
The following example shows how to map a range of VLANs to instance 2:
Device(config-mst)# instance 2 vlans 1-100 Device(config-mst)#The following example shows how to map a VLAN to instance 5:
Device(config-mst)# instance 5 vlans 1100 Device(config-mst)#The following example shows how to move a range of VLANs from instance 2 to the CIST instance:
Device(config-mst)# no instance 2 vlans 40-60 Device(config-mst)#The following example shows how to move all the VLANs that are mapped to instance 2 back to the CIST instance:
Device(config-mst)# no instance 2 Device(config-mst)#Related Commands
Command
Description
name (MST configuration mode)
Sets the name of an MST region.
revision
Sets the revision number for the MST configuration.
show
Verifies the MST configuration.
show spanning-tree mst
Displays the information about the MST protocol.
spanning-tree mist configuration
Enters MST configuration mode.
l2protocol forward
To process or forward layer 2 Bridge Protocol Data Units (BPDU), use the l2protocol forward command in the interface configuration mode. To disable the command, use the no form of this command.
Usage Guidelines
This command is supported on the switchport main interface, layer 3 port main interface, Ethernet Virtual Circuits (EVCs), and on UNI-C and UNI-S ports. Ingress BPDUs that are processed by a service instance with l2protocol-forward configured, are treated as normal data locally on the same box, but they are sent as BPDUs on any egress trunk interfaces, outside the box.
