The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.
To assign an Ethernet port to an EtherChannel group, or to enable an EtherChannel mode, or both, use the channel-group command in interface configuration mode. To remove an Ethernet port from an EtherChannel group, use the no form of this command.
channel-group channel-group-number mode { active | auto [ non-silent ] | desirable [ non-silent ] | on | passive }
no channel-group
channel-group-number |
Channel group number. The range is 1 to 128. |
mode |
Specifies the EtherChannel mode. |
active | Unconditionally enables Link Aggregation Control Protocol (LACP). |
auto | Enables the Port Aggregation Protocol (PAgP) only if a PAgP device is detected. |
non-silent | (Optional) Configures the interface for nonsilent operation when connected to a partner that is PAgP-capable. Use in PAgP mode with the auto or desirable keyword when traffic is expected from the other device. |
desirable | Unconditionally enables PAgP. |
on | Enables the on mode. |
passive | Enables LACP only if a LACP device is detected. |
No channel groups are assigned.
No mode is configured.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
For Layer 2 EtherChannels, the channel-group command automatically creates the port-channel interface when the channel group gets its first physical port. You do not have to use the interface port-channel command in global configuration mode to manually create a port-channel interface. If you create the port-channel interface first, the channel-group-number can be the same as the port-channel-number, or you can use a new number. If you use a new number, the channel-group command dynamically creates a new port channel.
Although it is not necessary to disable the IP address that is assigned to a physical port that is part of a channel group, we strongly recommend that you do so.
You create Layer 3 port channels by using the interface port-channel command followed by the no switchport interface configuration command. Manually configure the port-channel logical interface before putting the interface into the channel group.
After you configure an EtherChannel, configuration changes that you make on the port-channel interface apply to all the physical ports assigned to the port-channel interface. Configuration changes applied to the physical port affect only the port where you apply the configuration. To change the parameters of all ports in an EtherChannel, apply configuration commands to the port-channel interface, for example, spanning-tree commands or commands to configure a Layer 2 EtherChannel as a trunk.
Active mode places a port into a negotiating state in which the port initiates negotiations with other ports by sending LACP packets. A channel is formed with another port group in either the active or passive mode.
Auto mode places a port into a passive negotiating state in which the port responds to PAgP packets it receives but does not start PAgP packet negotiation. A channel is formed only with another port group in desirable mode. When auto is enabled, silent operation is the default.
Desirable mode places a port into an active negotiating state in which the port starts negotiations with other ports by sending PAgP packets. An EtherChannel is formed with another port group that is in the desirable or auto mode. When desirable is enabled, silent operation is the default.
If you do not specify non-silent with the auto or desirable mode, silent is assumed. The silent mode is used when the controller is connected to a device that is not PAgP-capable and rarely, if ever, sends packets. An example of a silent partner is a file server or a packet analyzer that is not generating traffic. In this case, running PAgP on a physical port prevents that port from ever becoming operational. However, it allows PAgP to operate, to attach the port to a channel group, and to use the port for transmission. Both ends of the link cannot be set to silent.
In on mode, a usable EtherChannel exists only when both connected port groups are in the on mode.
Caution | Use care when using the on mode. This is a manual configuration, and ports on both ends of the EtherChannel must have the same configuration. If the group is misconfigured, packet loss or spanning-tree loops can occur. |
Passive mode places a port into a negotiating state in which the port responds to received LACP packets but does not initiate LACP packet negotiation. A channel is formed only with another port group in active mode.
Do not configure an EtherChannel in both the PAgP and LACP modes. EtherChannel groups running PAgP and LACP can coexist on the same controller or on different controllers in the stack (but not in a cross-stack configuration). Individual EtherChannel groups can run either PAgP or LACP, but they cannot interoperate.
If you set the protocol by using the channel-protocol interface configuration command, the setting is not overridden by the channel-group interface configuration command.
Do not configure a port that is an active or a not-yet-active member of an EtherChannel as an IEEE 802.1x port. If you try to enable IEEE 802.1x authentication on an EtherChannel port, an error message appears, and IEEE 802.1x authentication is not enabled.
Do not configure a secure port as part of an EtherChannel or configure an EtherChannel port as a secure port.
For a complete list of configuration guidelines, see the “Configuring EtherChannels” chapter in the software configuration guide for this release.
Caution | Do not enable Layer 3 addresses on the physical EtherChannel ports. Do not assign bridge groups on the physical EtherChannel ports because it creates loops. |
This example shows how to configure an EtherChannel on a single controller in the stack. It assigns two static-access ports in VLAN 10 to channel 5 with the PAgP mode desirable:
Controller# configure terminal Controller(config)# interface range gigabitethernet2/0/1 -2 Controller(config-if-range)# switchport mode access Controller(config-if-range)# switchport access vlan 10 Controller(config-if-range)# channel-group 5 mode desirable Controller(config-if-range)# end
This example shows how to configure an EtherChannel on a single controller in the stack. It assigns two static-access ports in VLAN 10 to channel 5 with the LACP mode active:
Controller# configure terminal Controller(config)# interface range gigabitethernet2/0/1 -2 Controller(config-if-range)# switchport mode access Controller(config-if-range)# switchport access vlan 10 Controller(config-if-range)# channel-group 5 mode active Controller(config-if-range)# end
This example shows how to configure a cross-stack EtherChannel in a controller stack. It uses LACP passive mode and assigns two ports on stack member 2 and one port on stack member 3 as static-access ports in VLAN 10 to channel 5:
Controller# configure terminal Controller(config)# interface range gigabitethernet2/0/4 -5 Controller(config-if-range)# switchport mode access Controller(config-if-range)# switchport access vlan 10 Controller(config-if-range)# channel-group 5 mode passive Controller(config-if-range)# exit Controller(config)# interface gigabitethernet3/0/3 Controller(config-if)# switchport mode access Controller(config-if)# switchport access vlan 10 Controller(config-if)# channel-group 5 mode passive Controller(config-if)# exit
You can verify your settings by entering the show running-config privileged EXEC command.
Command | Description |
Restricts the protocol used on a port to manage channeling. | |
Accesses or creates a port channel. | |
Displays EtherChannel information for a channel. | |
Displays LACP channel-group information. | |
Displays Port Aggregation Protocol (PAgP) channel-group information. |
To restrict the protocol used on a port to manage channeling, use the channel-protocol command in interface configuration mode. To return to the default setting, use the no form of this command.
channel-protocol { lacp | pagp }
no channel-protocol
lacp |
Configures an EtherChannel with the Link Aggregation Control Protocol (LACP). |
pagp | Configures an EtherChannel with the Port Aggregation Protocol (PAgP). |
No protocol is assigned to the EtherChannel.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
Use the channel-protocol command only to restrict a channel to LACP or PAgP. If you set the protocol by using the channel-protocol command, the setting is not overridden by the channel-group interface configuration command.
You must use the channel-group interface configuration command to configure the EtherChannel parameters. The channel-group command also can set the mode for the EtherChannel.
You cannot enable both the PAgP and LACP modes on an EtherChannel group.
PAgP and LACP are not compatible; both ends of a channel must use the same protocol.
You cannot configure PAgP on cross-stack configurations.
This example shows how to specify LACP as the protocol that manages the EtherChannel:
Controller(config-if)# channel-protocol lacp
You can verify your settings by entering the show etherchannel [channel-group-number] protocol privileged EXEC command.
Command | Description |
Assigns an Ethernet port to an EtherChannel group, or enables an EtherChannel mode, or both. | |
Displays EtherChannel information for a channel. |
To clear Link Aggregation Control Protocol (LACP) channel-group counters, use the clear lacp command in privileged EXEC mode.
clear lacp [ channel-group-number ] counters
channel-group-number |
(Optional) Channel group number. The range is 1 to 128. |
counters |
Clears traffic counters. |
None
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
You can clear all counters by using the clear lacp counters command, or you can clear only the counters for the specified channel group by using the clear lacp channel-group-number counters command.
This example shows how to clear all channel-group information:
Controller# clear lacp counters
This example shows how to clear LACP traffic counters for group 4:
Controller# clear lacp 4 counters
You can verify that the information was deleted by entering the show lacp counters or the show lacp channel-group-number counters privileged EXEC command.
Command | Description |
Displays LACP channel-group information. |
To clear the Port Aggregation Protocol (PAgP) channel-group information, use the clear pagp command in privileged EXEC mode.
clear pagp [ channel-group-number ] counters
channel-group-number |
(Optional) Channel group number. The range is 1 to 128. |
counters |
Clears traffic counters. |
None
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
You can clear all counters by using the clear pagp counters command, or you can clear only the counters for the specified channel group by using the clear pagp channel-group-number counters command.
This example shows how to clear all channel-group information:
Controller# clear pagp counters
This example shows how to clear PAgP traffic counters for group 10:
Controller# clear pagp 10 counters
You can verify that the information was deleted by entering the show pagp privileged EXEC command.
Command | Description |
Enables debugging of PAgP. | |
Displays Port Aggregation Protocol (PAgP) channel-group information. |
To enable debugging of EtherChannels, use the debug etherchannel command in privileged EXEC mode. To disable debugging, use the no form of the command.
debug etherchannel [ all | detail | error | event | idb ]
no debug etherchannel [ all | detail | error | event | idb ]
all |
(Optional) Displays all EtherChannel debug messages. |
detail |
(Optional) Displays detailed EtherChannel debug messages. |
error | (Optional) Displays EtherChannel error debug messages. |
event | (Optional) Displays EtherChannel event messages. |
idb | (Optional) Displays PAgP interface descriptor block debug messages. |
Debugging is disabled.
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
The undebug etherchannel command is the same as the no debug etherchannel command.
Note | Although the linecard keyword is displayed in the command-line help, it is not supported. |
When you enable debugging on a stack, it is enabled only on the active controller. To enable debugging on the standby controller, start a session from the active controller by using the session switch-number command in privileged EXEC mode. Enter the debug command at the command-line prompt of the standby controller.
To enable debugging on the standby controller without first starting a session on the active controller, use the remote command switch-number LINE command in privileged EXEC mode.
This example shows how to display all EtherChannel debug messages:
Controller# debug etherchannel all
This example shows how to display debug messages related to EtherChannel events:
Controller# debug etherchannel event
Command | Description |
Displays EtherChannel information for a channel. |
To enable debugging of Link Aggregation Control Protocol (LACP) activity, use the debug lacp command in privileged EXEC mode. To disable LACP debugging, use the no form of this command.
debug lacp [ all | event | fsm | misc | packet ]
no debug lacp [ all | event | fsm | misc | packet ]
all |
(Optional) Displays all LACP debug messages. |
event |
(Optional) Displays LACP event debug messages. |
fsm | (Optional) Displays messages about changes within the LACP finite state machine. |
misc | (Optional) Displays miscellaneous LACP debug messages. |
packet | (Optional) Displays the receiving and transmitting LACP control packets. |
Debugging is disabled.
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
The undebug etherchannel command is the same as the no debug etherchannel command.
When you enable debugging on a stack, it is enabled only on the active controller. To enable debugging on the standby controller, start a session from the active controller by using the session switch-number command in privileged EXEC mode. Enter the debug command at the command-line prompt of the standby controller.
To enable debugging on the standby controller without first starting a session on the active controller, use the remote command switch-number LINE command in privileged EXEC mode.
This example shows how to display all LACP debug messages:
Controller# debug LACP all
This example shows how to display debug messages related to LACP events:
Controller# debug LACP event
To enable debugging of Port Aggregation Protocol (PAgP) activity, use the debug pagp command in privileged EXEC mode. To disable PAgP debugging, use the no form of this command.
debug pagp [ all | dual-active | event | fsm | misc | packet ]
no debug pagp [ all | dual-active | event | fsm | misc | packet ]
all |
(Optional) Displays all PAgP debug messages. |
dual-active | (Optional) Displays dual-active detection messages. |
event |
(Optional) Displays PAgP event debug messages. |
fsm | (Optional) Displays messages about changes within the PAgP finite state machine. |
misc | (Optional) Displays miscellaneous PAgP debug messages. |
packet | (Optional) Displays the receiving and transmitting PAgP control packets. |
Debugging is disabled.
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
The undebug pagp command is the same as the no debug pagp command.
When you enable debugging on a stack, it is enabled only on the active controller. To enable debugging on the standby controller, start a session from the active controller by using the session switch-number command in privileged EXEC mode. Enter the debug command at the command-line prompt of the standby controller.
To enable debugging on the standby controller without first starting a session on the active controller, use the remote command switch-number LINE command in privileged EXEC mode.
This example shows how to display all PAgP debug messages:
Controller# debug pagp all
This example shows how to display debug messages related to PAgP events:
Controller# debug pagp event
To enable debugging of the platform-dependent port manager software module, use the debug platform pm command in privileged EXEC mode. To disable debugging, use the no form of this command.
all |
Displays all port manager debug messages. |
counters |
Displays counters for remote procedure call (RPC) debug messages. |
errdisable |
Displays error-disabled-related events debug messages. |
if-numbers |
Displays interface-number translation event debug messages. |
link-status |
Displays interface link-detection event debug messages. |
platform |
Displays port manager function event debug messages. |
pm-vectors |
Displays port manager vector-related event debug messages. |
detail |
(Optional) Displays vector-function details. |
vlans |
Displays VLAN creation and deletion event debug messages. |
Debugging is disabled.
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
The undebug platform pm command is the same as the no debug platform pm command.
When you enable debugging on a stack, it is enabled only on the active controller. To enable debugging on the standby controller, start a session from the active controller by using the session switch-number command in privileged EXEC mode. Enter the debug command at the command-line prompt of the standby controller.
To enable debugging on the standby controller without first starting a session on the active controller, use the remote command switch-number LINE command in privileged EXEC mode.
This example shows how to display debug messages related to the creation and deletion of VLANs:
Controller# debug platform pm vlans
To enable debugging of the platform-dependent UniDirectional Link Detection (UDLD) software, use the debug platform udld command in privileged EXEC mode. To disable debugging, use the no form of this command.
error |
(Optional) Displays error condition debug messages. |
Debugging is disabled.
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
The undebug platform udld command is the same as the no debug platform udld command.
To access or create a port channel, use the interface port-channel command in global configuration mode. Use the no form of this command to remove the port channel.
interface port-channel port-channel-number
no interface port-channel
port-channel-number |
Channel group number. The range is 1 to 128. |
No port channel logical interfaces are defined.
Global configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
For Layer 2 EtherChannels, you do not have to create a port-channel interface before assigning physical ports to a channel group. Instead, you can use the channel-group interface configuration command, which automatically creates the port-channel interface when the channel group obtains its first physical port. If you create the port-channel interface first, the channel-group-number can be the same as the port-channel-number, or you can use a new number. If you use a new number, the channel-group command dynamically creates a new port channel.
You create Layer 3 port channels by using the interface port-channel command followed by the no switchport interface configuration command. You should manually configure the port-channel logical interface before putting the interface into the channel group.
Only one port channel in a channel group is allowed.
Caution | When using a port-channel interface as a routed port, do not assign Layer 3 addresses on the physical ports that are assigned to the channel group. |
Caution | Do not assign bridge groups on the physical ports in a channel group used as a Layer 3 port channel interface because it creates loops. You must also disable spanning tree. |
Follow these guidelines when you use the interface port-channel command:
For a complete list of configuration guidelines, see the “Configuring EtherChannels” chapter in the software configuration guide for this release.
This example shows how to create a port channel interface with a port channel number of 5:
Controller(config)# interface port-channel 5
You can verify your setting by entering the show running-config privileged EXEC or show etherchannel channel-group-number detail privileged EXEC command.
Command | Description |
Assigns an Ethernet port to an EtherChannel group, or enables an EtherChannel mode, or both. | |
Displays EtherChannel information for a channel. |
To define the maximum number of active LACP ports allowed in a port channel, use the lacp max-bundle command in interface configuration mode. To return to the default setting, use the no form of this command.
lacp max-bundle max_bundle_number
no lacp max-bundle
max_bundle_number |
The maximum number of active LACP ports in the port channel. The range is 1 to 8. The default is 8. |
None
Interface configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.3SE |
This command was introduced. |
An LACP channel group can have up to 16 Ethernet ports of the same type. Up to eight ports can be active, and up to eight ports can be in hot-standby mode. When there are more than eight ports in an LACP channel group, the controller on the controlling end of the link uses port priorities to determine which ports are bundled into the channel and which ports are put in hot-standby mode. Port priorities on the other controller (the noncontrolling end of the link) are ignored.
The lacp max-bundle command must specify a number greater than the number specified by the port-channel min-links command.
Use the show etherchannel summary privileged EXEC command to see which ports are in the hot-standby mode (denoted with an H port-state flag in the output display).
This example shows how to specify a maximum of five active LACP ports in port channel 2:
Controller(config)# interface port-channel 2 Controller(config-if)# lacp max-bundle 5
Command | Description |
Specifies the minimum number of LACP ports that must be in the link-up state and bundled in the EtherChannel in order for the port channel to become active. |
To configure the port priority for the Link Aggregation Control Protocol (LACP), use the lacp port-priority command in interface configuration mode. To return to the default setting, use the no form of this command.
lacp port-priority priority
no lacp port-priority
priority |
Port priority for LACP. The range is 1 to 65535. |
The default is 32768.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
The lacp port-priority interface configuration command determines which ports are bundled and which ports are put in hot-standby mode when there are more than eight ports in an LACP channel group.
An LACP channel group can have up to 16 Ethernet ports of the same type. Up to eight ports can be active, and up to eight ports can be in standby mode.
In port-priority comparisons, a numerically lower value has a higher priority: When there are more than eight ports in an LACP channel group, the eight ports with the numerically lowest values (highest priority values) for LACP port priority are bundled into the channel group, and the lower-priority ports are put in hot-standby mode. If two or more ports have the same LACP port priority (for example, they are configured with the default setting of 65535), then an internal value for the port number determines the priority.
Note | The LACP port priorities are only effective if the ports are on the controller that controls the LACP link. See the lacp system-priority global configuration command for determining which controller controls the link. |
Use the show lacp internal privileged EXEC command to display LACP port priorities and internal port number values.
For information about configuring LACP on physical ports, see the configuration guide for this release.
This example shows how to configure the LACP port priority on a port:
Controller# interface gigabitethernet2/0/1 Controller(config-if)# lacp port-priority 1000
You can verify your settings by entering the show lacp [channel-group-number] internal privileged EXEC command.
Command | Description |
Assigns an Ethernet port to an EtherChannel group, or enables an EtherChannel mode, or both. | |
Configures the LACP system priority. | |
Displays LACP channel-group information. |
To configure the system priority for the Link Aggregation Control Protocol (LACP), use the lacp system-priority command in global configuration mode on the controller. To return to the default setting, use the no form of this command.
lacp system-priority priority
no lacp system-priority
priority |
System priority for LACP. The range is 1 to 65535. |
The default is 32768.
Global configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
The lacp system-priority command determines which controller in an LACP link controls port priorities.
An LACP channel group can have up to 16 Ethernet ports of the same type. Up to eight ports can be active, and up to eight ports can be in standby mode. When there are more than eight ports in an LACP channel group, the controller on the controlling end of the link uses port priorities to determine which ports are bundled into the channel and which ports are put in hot-standby mode. Port priorities on the other controller (the noncontrolling end of the link) are ignored.
In priority comparisons, numerically lower values have a higher priority. Therefore, the system with the numerically lower value (higher priority value) for LACP system priority becomes the controlling system. If both controllers have the same LACP system priority (for example, they are both configured with the default setting of 32768), the LACP system ID (the controller MAC address) determines which controller is in control.
The lacp system-priority command applies to all LACP EtherChannels on the controller.
Use the show etherchannel summary privileged EXEC command to see which ports are in the hot-standby mode (denoted with an H port-state flag in the output display).
This example shows how to set the LACP system priority:
Controller(config)# lacp system-priority 20000
You can verify your settings by entering the show lacp sys-id privileged EXEC command.
Command | Description |
Assigns an Ethernet port to an EtherChannel group, or enables an EtherChannel mode, or both. | |
Configures the port priority for the Link Aggregation Control Protocol (LACP). | |
Displays LACP channel-group information. |
To learn the source address of incoming packets received from an EtherChannel port, use the pagp learn-method command in interface configuration mode. To return to the default setting, use the no form of this command.
pagp learn-method { aggregation-port | physical-port }
no pagp learn-method
aggregation-port |
Specifies address learning on the logical port channel. The controller sends packets to the source using any port in the EtherChannel. This setting is the default. With aggregation-port learning, it is not important on which physical port the packet arrives. |
physical-port |
Specifies address learning on the physical port within the EtherChannel. The controller sends packets to the source using the same port in the EtherChannel from which it learned the source address. The other end of the channel uses the same port in the channel for a particular destination MAC or IP address. |
The default is aggregation-port (logical port channel).
Interface configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
The learn method must be configured the same at both ends of the link.
The controller supports address learning only on aggregate ports even though the physical-port keyword is provided in the command-line interface (CLI). The pagp learn-method and the pagp port-priority interface configuration commands have no effect on the controller hardware, but they are required for PAgP interoperability with devices that only support address learning by physical ports.
When the link partner to the controller is a physical learner, we recommend that you configure the controller as a physical-port learner by using the pagp learn-method physical-port interface configuration command. We also recommend that you set the load-distribution method based on the source MAC address by using the port-channel load-balance src-mac global configuration command. Use the pagp learn-method interface configuration command only in this situation.
This example shows how to set the learning method to learn the address on the physical port within the EtherChannel:
Controller(config-if)# pagp learn-method physical-port
This example shows how to set the learning method to learn the address on the port channel within the EtherChannel:
Controller(config-if)# pagp learn-method aggregation-port
You can verify your settings by entering the show running-config privileged EXEC command or the show pagp channel-group-number internal privileged EXEC command.
Command | Description |
Selects a port over which all traffic through the EtherChannel is sent. | |
Displays Port Aggregation Protocol (PAgP) channel-group information. |
To select a port over which all Port Aggregation Protocol (PAgP) traffic through the EtherChannel is sent, use the pagp port-priority command in interface configuration mode. If all unused ports in the EtherChannel are in hot-standby mode, they can be placed into operation if the currently selected port and link fails. To return to the default setting, use the no form of this command.
pagp port-priority priority
no pagp port-priority
priority |
Priority number. The range is from 0 to 255. |
The default is 128.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
The physical port with the highest priority that is operational and has membership in the same EtherChannel is the one selected for PAgP transmission.
The controller supports address learning only on aggregate ports even though the physical-port keyword is provided in the command-line interface (CLI). The pagp learn-method and the pagp port-priority interface configuration commands have no effect on the controller hardware, but they are required for PAgP interoperability with devices that only support address learning by physical ports, such as the Catalyst 1900 switch.
When the link partner to the controller is a physical learner, we recommend that you configure the controller as a physical-port learner by using the pagp learn-method physical-port interface configuration command. We also recommend that you set the load-distribution method based on the source MAC address by using the port-channel load-balance src-mac global configuration command. Use the pagp learn-method interface configuration command only in this situation.
This example shows how to set the port priority to 200:
Controller(config-if)# pagp port-priority 200
You can verify your setting by entering the show running-config privileged EXEC command or the show pagp channel-group-number internal privileged EXEC command.
Command | Description |
Provides the ability to learn the source address of incoming packets. | |
Sets the load-distribution method among the ports in the EtherChannel. | |
Displays Port Aggregation Protocol (PAgP) channel-group information. |
To set the load-distribution method among the ports in the EtherChannel, use the port-channel load-balance command in global configuration mode. To reset the load-balancing mechanism to the default setting, use the no form of this command.
port-channel load-balance { dst-ip | dst-mac | dst-mixed-ip-port | dst-port | extended | src-dst-ip | src-dst-mac | src-dst-mixed-ip-port | src-dst-port | src-ip | src-mac | src-mixed-ip-port | src-port }
no port-channel load-balance
dst-ip |
Specifies load distribution based on the destination host IP address. |
dst-mac |
Specifies load distribution based on the destination host MAC address. Packets to the same destination are sent on the same port, but packets to different destinations are sent on different ports in the channel. |
dst-mixed-ip-port |
Specifies load distribution based on the destination IPv4 or IPv6 address and the TCP/UDP (Layer 4) port number. |
dst-port |
Specifies load distribution based on the destination TCP/UDP (Layer 4) port number for both IPv4 and IPv6. |
extended |
Sets extended load balance methods among the ports in the EtherChannel. See the port-channel load-balance extended command. |
src-dst-ip |
Specifies load distribution based on the source and destination host IP address. |
src-dst-mac |
Specifies load distribution based on the source and destination host MAC address. |
src-dst-mixed-ip-port |
Specifies load distribution based on the source and destination host IP address and TCP/UDP (layer 4) port number. |
src-dst-port |
Specifies load distribution based on the source and destination TCP/UDP (Layer 4) port number. |
src-ip |
Specifies load distribution based on the source host IP address. |
src-mac |
Specifies load distribution based on the source MAC address. Packets from different hosts use different ports in the channel, but packets from the same host use the same port. |
src-mixed-ip-port |
Specifies load distribution based on the source host IP address and TCP/UDP (Layer 4) port number. |
src-port |
Specifies load distribution based on the TCP/UDP (Layer 4) port number. |
The default is src-mac.
Global configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
You can verify your setting by entering the show running-config privileged EXEC command or the show etherchannel load-balance privileged EXEC command.
This example shows how to set the load-distribution method to dst-mac:
Controller(config)# port-channel load-balance dst-mac
To set combinations of load-distribution methods among the ports in the EtherChannel, use the port-channel load-balance extended command in global configuration mode. To reset the extended load-balancing mechanism to the default setting, use the no form of this command.
port-channel load-balance extended [ dst-ip | dst-mac | dst-port | ipv6-label | l3-proto | src-ip | src-mac | src-port ]
no port-channel load-balance extended
dst-ip |
(Optional) Specifies load distribution based on the destination host IP address. |
dst-mac |
(Optional) Specifies load distribution based on the destination host MAC address. Packets to the same destination are sent on the same port, but packets to different destinations are sent on different ports in the channel. |
dst-port |
(Optional) Specifies load distribution based on the destination TCP/UDP (Layer 4) port number for both IPv4 and IPv6. |
ipv6-label |
(Optional) Specifies load distribution based on the source MAC address and IPv6 flow label. |
l3-proto |
(Optional) Specifies load distribution based on the source MAC address and Layer 3 protocols. |
src-ip |
(Optional) Specifies load distribution based on the source host IP address. |
src-mac |
(Optional) Specifies load distribution based on the source MAC address. Packets from different hosts use different ports in the channel, but packets from the same host use the same port. |
src-port |
(Optional) Specifies load distribution based on the TCP/UDP (Layer 4) port number. |
The default is src-mac.
Global configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
For information about when to use these forwarding methods, see the Layer 2 Configuration Guide (Cisco WLC 5700 Series) for this release.
You can verify your setting by entering the show running-config privileged EXEC command or the show etherchannel load-balance privileged EXEC command.
This example shows how to set the extended load-distribution method:
Controller(config)# port-channel load-balance extended dst-ip dst-mac src-ip
To define the minimum number of LACP ports that must be bundled in the link-up state and bundled in the EtherChannel in order that a port channel becomes active, use the port-channel min-links command in interface configuration mode. To return to the default setting, use the no form of this command.
port-channel min-links min_links_number
no port-channel min-links
min_links_number |
The minimum number of active LACP ports in the port channel. The range is 2 to 8. The default is 1. |
None
Interface configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.3SE |
This command was introduced. |
An LACP channel group can have up to 16 Ethernet ports of the same type. Up to eight ports can be active, and up to eight ports can be in hot-standby mode. When there are more than eight ports in an LACP channel group, the controller on the controlling end of the link uses port priorities to determine which ports are bundled into the channel and which ports are put in hot-standby mode. Port priorities on the other controller (the noncontrolling end of the link) are ignored.
The port-channel min-links command must specify a number a less than the number specified by the lacp max-bundle command.
Use the show etherchannel summary privileged EXEC command to see which ports are in the hot-standby mode (denoted with an H port-state flag in the output display).
This example shows how to specify a minimum of three active LACP ports before port channel 2 becomes active:
Controller(config)# interface port-channel 2 Controller(config-if)# port-channel min-links 3
Command | Description |
Specifies the maximum number of LACP ports allowed in a port channel. |
To display EtherChannel information for a channel, use the show etherchannel command in user EXEC mode.
show etherchannel [ channel-group-number | { detail | port | port-channel | protocol | summary } ] | [ detail | load-balance | port | port-channel | protocol | summary ]
channel-group-number |
(Optional) Channel group number. The range is 1 to 128. |
detail |
(Optional) Displays detailed EtherChannel information. |
load-balance | (Optional) Displays the load-balance or frame-distribution scheme among ports in the port channel. |
port | (Optional) Displays EtherChannel port information. |
port-channel | (Optional) Displays port-channel information. |
protocol | (Optional) Displays the protocol that is being used in the channel. |
summary | (Optional) Displays a one-line summary per channel group. |
None
User EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
If you do not specify a channel group number, all channel groups are displayed.
In the output, the passive port list field is displayed only for Layer 3 port channels. This field means that the physical port, which is still not up, is configured to be in the channel group (and indirectly is in the only port channel in the channel group).
This is an example of output from the show etherchannel channel-group-number detail command:
Controller> show etherchannel 1 detail
Group state = L2
Ports: 2 Maxports = 16
Port-channels: 1 Max Port-channels = 16
Protocol: LACP
Ports in the group:
-------------------
Port: Gi1/0/1
------------
Port state = Up Mstr In-Bndl
Channel group = 1 Mode = Active Gcchange = -
Port-channel = Po1GC = - Pseudo port-channel = Po1
Port index = 0Load = 0x00 Protocol = LACP
Flags: S - Device is sending Slow LACPDUs F - Device is sending fast LACPDU
A - Device is in active mode. P - Device is in passive mode.
Local information:
LACP port Admin Oper Port Port
Port Flags State Priority Key Key Number State
Gi1/0/1 SA bndl 32768 0x1 0x1 0x101 0x3D
Gi1/0/2 A bndl 32768 0x0 0x1 0x0 0x3D
Age of the port in the current state: 01d:20h:06m:04s
Port-channels in the group:
----------------------
Port-channel: Po1 (Primary Aggregator)
Age of the Port-channel = 01d:20h:20m:26s
Logical slot/port = 10/1 Number of ports = 2
HotStandBy port = null
Port state = Port-channel Ag-Inuse
Protocol = LACP
Ports in the Port-channel:
Index Load Port EC state No of bits
------+------+------+------------------+-----------
0 00 Gi1/0/1 Active 0
0 00 Gi1/0/2 Active 0
Time since last port bundled: 01d:20h:24m:44s Gi1/0/2
This is an example of output from the show etherchannel channel-group-number summary command:
Controller> show etherchannel 1 summary
Flags: D - down P - in port-channel
I - stand-alone s - suspended
H - Hot-standby (LACP only)
R - Layer3 S - Layer2
u - unsuitable for bundling
U - in use f - failed to allocate aggregator
d - default port
Number of channel-groups in use: 1
Number of aggregators: 1
Group Port-channel Protocol Ports
------+-------------+-----------+----------------------------------------
1 Po1(SU) LACP Gi1/0/1(P) Gi1/0/2(P)
This is an example of output from the show etherchannel channel-group-number port-channel command:
Controller> show etherchannel 1 port-channel
Port-channels in the group:
----------------------
Port-channel: Po1 (Primary Aggregator)
------------
Age of the Port-channel = 01d:20h:24m:50s
Logical slot/port = 10/1 Number of ports = 2
Logical slot/port = 10/1 Number of ports = 2
Port state = Port-channel Ag-Inuse
Protocol = LACP
Ports in the Port-channel:
Index Load Port EC state No of bits
------+------+------+------------------+-----------
0 00 Gi1/0/1 Active 0
0 00 Gi1/0/2 Active 0
Time since last port bundled: 01d:20h:24m:44s Gi1/0/2
This is an example of output from show etherchannel protocol command:
Controller# show etherchannel protocol
Channel-group listing:
-----------------------
Group: 1
----------
Protocol: LACP
Group: 2
----------
Protocol: PAgP
Command | Description |
Assigns an Ethernet port to an EtherChannel group, or enables an EtherChannel mode, or both. | |
Restricts the protocol used on a port to manage channeling. | |
Accesses or creates a port channel. |
To display Link Aggregation Control Protocol (LACP) channel-group information, use the show lacp command in user EXEC mode.
show lacp [ channel-group-number ] { counters | internal | neighbor | sys-id }
channel-group-number |
(Optional) Channel group number. The range is 1 to 128. |
counters |
Displays traffic information. |
internal | Displays internal information. |
neighbor | Displays neighbor information. |
sys-id | Displays the system identifier that is being used by LACP. The system identifier consists of the LACP system priority and the controller MAC address. |
None
User EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
You can enter any show lacp command to display the active channel-group information. To display specific channel information, enter the show lacp command with a channel-group number.
If you do not specify a channel group, information for all channel groups appears.
You can enter the channel-group-number to specify a channel group for all keywords except sys-id.
This is an example of output from the show lacp counters user EXEC command. The table that follows describes the fields in the display.
Controller> show lacp counters
LACPDUs Marker Marker Response LACPDUs
Port Sent Recv Sent Recv Sent Recv Pkts Err
---------------------------------------------------------------------
Channel group:1
Gi2/0/1 19 10 0 0 0 0 0
Gi2/0/2 14 6 0 0 0 0 0
Field |
Description |
---|---|
LACPDUs Sent and Recv |
The number of LACP packets sent and received by a port. |
Marker Sent and Recv |
The number of LACP marker packets sent and received by a port. |
Marker Response Sent and Recv |
The number of LACP marker response packets sent and received by a port. |
LACPDUs Pkts and Err |
The number of unknown and illegal packets received by LACP for a port. |
This is an example of output from the show lacp internal command:
Controller> show lacp 1 internal
Flags: S - Device is requesting Slow LACPDUs
F - Device is requesting Fast LACPDUs
A - Device is in Active mode P - Device is in Passive mode
Channel group 1
LACP port Admin Oper Port Port
Port Flags State Priority Key Key Number State
Gi2/0/1 SA bndl 32768 0x3 0x3 0x4 0x3D
Gi2/0/2 SA bndl 32768 0x3 0x3 0x5 0x3D
The following table describes the fields in the display:
This is an example of output from the show lacp neighbor command:
Controller> show lacp neighbor
Flags: S - Device is sending Slow LACPDUs F - Device is sending Fast LACPDUs
A - Device is in Active mode P - Device is in Passive mode
Channel group 3 neighbors
Partner’s information:
Partner Partner Partner
Port System ID Port Number Age Flags
Gi2/0/1 32768,0007.eb49.5e80 0xC 19s SP
LACP Partner Partner Partner
Port Priority Oper Key Port State
32768 0x3 0x3C
Partner’s information:
Partner Partner Partner
Port System ID Port Number Age Flags
Gi2/0/2 32768,0007.eb49.5e80 0xD 15s SP
LACP Partner Partner Partner
Port Priority Oper Key Port State
32768 0x3 0x3C
This is an example of output from the show lacp sys-id command:
Controller> show lacp sys-id
32765,0002.4b29.3a00
The system identification is made up of the system priority and the system MAC address. The first two bytes are the system priority, and the last six bytes are the globally administered individual MAC address associated to the system.
Command | Description |
Clears the LACP channel-group information. | |
Configures the port priority for the Link Aggregation Control Protocol (LACP). | |
Configures the LACP system priority. |
To display Port Aggregation Protocol (PAgP) channel-group information, use the show pagp command in EXEC mode.
show pagp [ channel-group-number ] { counters | dual-active | internal | neighbor }
channel-group-number |
(Optional) Channel group number. The range is 1 to 128. |
counters |
Displays traffic information. |
dual-active |
Displays the dual-active status. |
internal |
Displays internal information. |
neighbor |
Displays neighbor information. |
None
User EXEC
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
You can enter any show pagp command to display the active channel-group information. To display the nonactive information, enter the show pagp command with a channel-group number.
This is an example of output from the show pagp 1 counters command:
Controller> show pagp 1 counters
Information Flush
Port Sent Recv Sent Recv
----------------------------------------
Channel group: 1
Gi1/0/1 45 42 0 0
Gi1/0/2 45 41 0 0
This is an example of output from the show pagp dual-active command:
Controller> show pagp dual-active PAgP dual-active detection enabled: Yes PAgP dual-active version: 1.1 Channel group 1 Dual-Active Partner Partner Partner Port Detect Capable Name Port Version Gi1/0/1 No Controller Gi3/0/3 N/A Gi1/0/2 No Controller Gi3/0/4 N/A <output truncated>
This is an example of output from the show pagp 1 internal command:
Controller> show pagp 1 internal
Flags: S - Device is sending Slow hello. C - Device is in Consistent state.
A - Device is in Auto mode.
Timers: H - Hello timer is running. Q - Quit timer is running.
S - Switching timer is running. I - Interface timer is running.
Channel group 1
Hello Partner PAgP Learning Group
Port Flags State Timers Interval Count Priority Method Ifindex
Gi1/0/1 SC U6/S7 H 30s 1 128 Any 16
Gi1/0/2 SC U6/S7 H 30s 1 128 Any 16
This is an example of output from the show pagp 1 neighbor command:
Controller> show pagp 1 neighbor Flags: S - Device is sending Slow hello. C - Device is in Consistent state. A - Device is in Auto mode. P - Device learns on physical port. Channel group 1 neighbors Partner Partner Partner Partner Group Port Name Device ID Port Age Flags Cap. Gi1/0/1 controller-p2 0002.4b29.4600 Gi01//1 9s SC 10001 Gi1/0/2 controller-p2 0002.4b29.4600 Gi1/0/2 24s SC 10001
Command | Description |
Clears PAgP channel-group information. |
To display platform-dependent EtherChannel information, use the show platform etherchannel command in privileged EXEC mode.
show platform etherchannel channel-group-number { group-mask | load-balance mac src-mac dst-mac [ ip src-ip dst-ip [ port src-port dst-port ] ] }
channel-group-number |
Channel group number. The range is 1 to 128. |
group-mask |
Displays EtherChannel group mask. |
load-balance |
Tests EtherChannel load-balance hash algorithm. |
mac src-mac dst-mac |
Specifies the source and destination MAC addresses. |
ip src-ip dst-ip |
(Optional) Specifies the source and destination IP addresses. |
port src-port dst-port |
(Optional) Specifies the source and destination layer port numbers. |
None
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
Use this command only when you are working directly with a technical support representative while troubleshooting a problem.
Do not use this command unless a technical support representative asks you to do so.
To display platform-dependent port manager information, use the show platform pm command in privileged EXEC mode.
None
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
Use this command only when you are working directly with your technical support representative while troubleshooting a problem.
Do not use this command unless your technical support representative asks you to do so.
To display UniDirectional Link Detection (UDLD) administrative and operational status for all ports or the specified port, use the show udld command in user EXEC mode.
show udld [ Auto-Template | Capwap | GigabitEthernet | GroupVI | InternalInterface | Loopback | Null | Port-channel | TenGigabitEthernet | Tunnel | Vlan] interface_number
show udld neighbors
Auto-Template | (Optional) Displays UDLD operational status of the auto-template interface. The range is from 1 to 999. |
Capwap | (Optional) Displays UDLD operational status of the CAPWAP interface. The range is from 0 to 2147483647. |
GigabitEthernet | (Optional) Displays UDLD operational status of the GigabitEthernet interface. The range is from 0 to 9. |
GroupVI | (Optional) Displays UDLD operational status of the group virtual interface. The range is from 1 to 255. |
InternalInterface | (Optional) Displays UDLD operational status of the internal interface. The range is from 0 to 9. |
Loopback | (Optional) Displays UDLD operational status of the loopback interface. The range is from 0 to 2147483647. |
Null | (Optional) Displays UDLD operational status of the null interface. |
Port-channel | (Optional) Displays UDLD operational status of the Ethernet channel interfaces. The range is from 1 to 128. |
TenGigabitEthernet | (Optional) Displays UDLD operational status of the Ten Gigabit Ethernet interface. The range is from 0 to 9. |
Tunnel | (Optional) Displays UDLD operational status of the tunnel interface. The range is from 0 to 2147483647. |
Vlan | (Optional) Displays UDLD operational status of the VLAN interface. The range is from 1 to 4095. |
interface-id |
(Optional) ID of the interface and port number. Valid interfaces include physical ports, VLANs, and port channels. |
neighbors | (Optional) Displays neighbor information only. |
None
User EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
If you do not enter an interface ID, administrative and operational UDLD status for all interfaces appear.
This is an example of output from the show udld interface-id command. For this display, UDLD is enabled on both ends of the link, and UDLD detects that the link is bidirectional. The table that follows describes the fields in this display.
Controller> show udld gigabitethernet2/0/1
Interface gi2/0/1
---
Port enable administrative configuration setting: Follows device default
Port enable operational state: Enabled
Current bidirectional state: Bidirectional
Current operational state: Advertisement - Single Neighbor detected
Message interval: 60
Time out interval: 5
Entry 1
Expiration time: 146
Device ID: 1
Current neighbor state: Bidirectional
Device name: Switch-A
Port ID: Gi2/0/1
Neighbor echo 1 device: Switch-B
Neighbor echo 1 port: Gi2/0/2
Message interval: 5
CDP Device name: Switch-A
Field |
Description |
---|---|
Interface |
The interface on the local device configured for UDLD. |
Port enable administrative configuration setting |
How UDLD is configured on the port. If UDLD is enabled or disabled, the port enable configuration setting is the same as the operational enable state. Otherwise, the enable operational setting depends on the global enable setting. |
Port enable operational state |
Operational state that shows whether UDLD is actually running on this port. |
Current bidirectional state |
The bidirectional state of the link. An unknown state appears if the link is down or if it is connected to an UDLD-incapable device. A bidirectional state appears if the link is a normal two-way connection to a UDLD-capable device. All other values mean miswiring. |
Current operational state |
The current phase of the UDLD state machine. For a normal bidirectional link, the state machine is most often in the Advertisement phase. |
Message interval |
How often advertisement messages are sent from the local device. Measured in seconds. |
Time out interval |
The time period, in seconds, that UDLD waits for echoes from a neighbor device during the detection window. |
Entry 1 |
Information from the first cache entry, which contains a copy of echo information received from the neighbor. |
Expiration time |
The amount of time in seconds remaining before this cache entry is aged out. |
Device ID |
The neighbor device identification. |
Current neighbor state |
The neighbor’s current state. If both the local and neighbor devices are running UDLD normally, the neighbor state and local state should be bidirectional. If the link is down or the neighbor is not UDLD-capable, no cache entries appear. |
Device name |
The device name or the system serial number of the neighbor. The system serial number appears if the device name is not set or is set to the default (Switch). |
Port ID |
The neighbor port ID enabled for UDLD. |
Neighbor echo 1 device |
The device name of the neighbors’ neighbor from which the echo originated. |
Neighbor echo 1 port |
The port number ID of the neighbor from which the echo originated. |
Message interval |
The rate, in seconds, at which the neighbor is sending advertisement messages. |
CDP device name |
The CDP device name or the system serial number. The system serial number appears if the device name is not set or is set to the default (Switch). |
This is an example of output from the show udld neighbors command:
Controller# show udld neighbors
Port Device Name Device ID Port-ID OperState
-------- -------------------- ---------- -------- --------------
Gi2/0/1 Switch-A 1 Gi2/0/1 Bidirectional
Gi3/0/1 Switch-A 2 Gi3/0/1 Bidirectional
Command | Description |
Enables aggressive or normal mode in UDLD or sets the configurable message timer time. | |
Enables UDLD on an individual interface or prevents a fiber-optic interface from being enabled by the udld global configuration command. | |
Resets all interfaces shut down by UDLD and permits traffic to pass through again. |
To put an interface that is in Layer 3 mode into Layer 2 mode for Layer 2 configuration, use the switchport command in interface configuration mode. To put an interface in Layer 3 mode, use the no form of this command.
switchport
no switchport
This command has no arguments or keywords.
By default, all interfaces are in Layer 2 mode.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
Use the no switchport command (without parameters) to set the interface to the routed-interface status and to erase all Layer 2 configurations. You must use this command before assigning an IP address to a routed port.
Note | This command is not supported on controllers running the LAN Base feature set. |
Entering the no switchport command shuts the port down and then reenables it, which might generate messages on the device to which the port is connected.
When you put an interface that is in Layer 2 mode into Layer 3 mode (or the reverse), the previous configuration information related to the affected interface might be lost, and the interface is returned to its default configuration.
Note | If an interface is configured as a Layer 3 interface, you must first enter the switchport command to configure the interface as a Layer 2 port. Then you can enter the switchport access vlan and switchport mode commands. |
The switchport command is not used on platforms that do not support Cisco-routed ports. All physical ports on such platforms are assumed to be Layer 2-switched interfaces.
You can verify the port status of an interface by entering the show running-config privileged EXEC command.
This example shows how to cause an interface to cease operating as a Layer 2 port and become a Cisco-routed port:
Controller(config-if)# no switchport
This example shows how to cause the port interface to cease operating as a Cisco-routed port and convert to a Layer 2 switched interface:
Controller(config-if)# switchport
To configure a port as a static-access port, use the switchport access vlan command in interface configuration mode. To reset the access mode to the default VLAN mode for the controller, use the no form of this command.
switchport access vlan vlan-id
no switchport access vlan
vlan-id |
VLAN ID of the access mode VLAN; the range is 1 to 4094. |
The default access VLAN and trunk interface native VLAN is a default VLAN corresponding to the platform or interface hardware.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
The port must be in access mode before the switchport access vlan command can take effect.
If the switchport mode is set to access vlan vlan-id, the port operates as a member of the specified VLAN. An access port can be assigned to only one VLAN.
The no switchport access command resets the access mode VLAN to the appropriate default VLAN for the device.
This example shows how to change a switched port interface that is operating in access mode to operate in VLAN 2 instead of the default VLAN:
Controller(config-if)# switchport access vlan 2
Command | Description |
Configures the VLAN membership mode of a port. |
To configure the VLAN membership mode of a port, use the switchport mode command in interface configuration mode. To reset the mode to the appropriate default for the device, use the no form of this command.
switchport mode { access | dynamic | { auto | desirable } | trunk }
noswitchport mode { access | dynamic | { auto | desirable } | trunk }
access |
Sets the port to access mode (either static-access or dynamic-access depending on the setting of the switchport access vlan interface configuration command). The port is set to access unconditionally and operates as a nontrunking, single VLAN interface that sends and receives nonencapsulated (non-tagged) frames. An access port can be assigned to only one VLAN. |
dynamic auto |
Sets the port trunking mode dynamic parameter to auto to specify that the interface convert the link to a trunk link. This is the default switchport mode. |
dynamic desirable |
Sets the port trunking mode dynamic parameter to desirable to specify that the interface actively attempt to convert the link to a trunk link. |
trunk |
Sets the port to trunk unconditionally. The port is a trunking VLAN Layer 2 interface. The port sends and receives encapsulated (tagged) frames that identify the VLAN of origination. A trunk is a point-to-point link between two controllers or between a controller and a router. |
The default mode is dynamic auto.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
Note | Although visible in the CLI, the dot1q-tunnel keyword is not supported. |
A configuration that uses the access,or trunk keywords takes effect only when you configure the port in the appropriate mode by using the switchport mode command. The static-access and trunk configuration are saved, but only one configuration is active at a time.
When you enter access mode, the interface changes to permanent nontrunking mode and negotiates to convert the link into a nontrunk link even if the neighboring interface does not agree to the change.
When you enter trunk mode, the interface changes to permanent trunking mode and negotiates to convert the link into a trunk link even if the interface connecting to it does not agree to the change.
When you enter dynamic auto mode, the interface converts the link to a trunk link if the neighboring interface is set to trunk or desirable mode.
When you enter dynamic desirable mode, the interface becomes a trunk interface if the neighboring interface is set to trunk, desirable, or auto mode.
To autonegotiate trunking, the interfaces must be in the same VLAN Trunking Protocol (VTP) domain. Trunk negotiation is managed by the Dynamic Trunking Protocol (DTP), which is a point-to-point protocol. However, some internetworking devices might forward DTP frames improperly, which could cause misconfigurations. To avoid this problem, configure interfaces connected to devices that do not support DTP to not forward DTP frames, which turns off DTP.
Access ports and trunk ports are mutually exclusive.
The IEEE 802.1x feature interacts with switchport modes in these ways:
You can verify your settings by entering the show interfaces interface-id switchport privileged EXEC command and examining information in the Administrative Mode and Operational Mode rows.
This example shows how to configure a port for access mode:
Controller(config)# interface gigabitethernet2/0/1 Controller(config-if)# switchport mode access
This example shows how set the port to dynamic desirable mode:
Controller(config)# interface gigabitethernet2/0/1 Controller(config-if)# switchport mode dynamic desirable
This example shows how to configure a port for trunk mode:
Controller(config)# interface gigabitethernet2/0/1 Controller(config-if)# switchport mode trunk
Command | Description |
Configures a port as a static-access port. |
To specify that Dynamic Trunking Protocol (DTP) negotiation packets are not sent on the Layer 2 interface, use the switchport nonegotiate command in interface configuration mode. Use the no form of this command to return to the default setting.
switchport nonegotiate
no switchport nonegotiate
This command has no arguments or keywords.
The default is to use DTP negotiation to learn the trunking status.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
The no switchport nonegotiate command removes nonegotiate status.
This command is valid only when the interface switchport mode is access or trunk (configured by using the switchport mode access or the switchport mode trunk interface configuration command). This command returns an error if you attempt to execute it in dynamic (auto or desirable) mode.
Internetworking devices that do not support DTP might forward DTP frames improperly and cause misconfigurations. To avoid this problem, turn off DTP by using the switchport nonegotiate command to configure the interfaces connected to devices that do not support DTP to not forward DTP frames.
When you enter the switchport nonegotiate command, DTP negotiation packets are not sent on the interface. The device does or does not trunk according to the mode parameter: access or trunk.
This example shows how to cause a port to refrain from negotiating trunking mode and to act as a trunk or access port (depending on the mode set):
Controller(config)# interface gigabitethernet2/0/1 Controller(config-if)# switchport nonegotiate
You can verify your setting by entering the show interfaces interface-id switchport privileged EXEC command.
Command | Description |
Configures the VLAN membership mode of a port. |
To enable aggressive or normal mode in the UniDirectional Link Detection (UDLD) and to set the configurable message timer time, use the udld command in global configuration mode. To disable aggressive or normal mode UDLD on all fiber-optic ports, use the no form of the command.
udld { aggressive | enable | message time message-timer-interval }
no udld { aggressive | enable | message }
aggressive |
Enables UDLD in aggressive mode on all fiber-optic interfaces. |
enable |
Enables UDLD in normal mode on all fiber-optic interfaces. |
message time message-timer-interval | Configures the period of time between UDLD probe messages on ports that are in the advertisement phase and are determined to be bidirectional. The range is 1 to 90 seconds. The default is 15 seconds. |
UDLD is disabled on all interfaces.
The message timer is set at 15 seconds.
Global configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
UDLD supports two modes of operation: normal (the default) and aggressive. In normal mode, UDLD detects unidirectional links due to misconnected interfaces on fiber-optic connections. In aggressive mode, UDLD also detects unidirectional links due to one-way traffic on fiber-optic and twisted-pair links and due to misconnected interfaces on fiber-optic links. For information about normal and aggressive modes, see the Catalyst 2960-X Switch Layer 2 Configuration GuideCatalyst 2960-XR Switch Layer 2 Configuration GuideLayer 2 Configuration Guide (Cisco WLC 5700 Series).
If you change the message time between probe packets, you are making a compromise between the detection speed and the CPU load. By decreasing the time, you can make the detection-response faster but increase the load on the CPU.
This command affects fiber-optic interfaces only. Use the udld interface configuration command to enable UDLD on other interface types.
You can use these commands to reset an interface shut down by UDLD:
This example shows how to enable UDLD on all fiber-optic interfaces:
Controller(config)# udld enable
You can verify your setting by entering the show udld privileged EXEC command.
Command | Description |
Displays UDLD administrative and operational status for all ports or the specified port. | |
Enables UDLD on an individual interface or prevents a fiber-optic interface from being enabled by the udld global configuration command. | |
Resets all interfaces shut down by UDLD and permits traffic to pass through again. |
To enable UniDirectional Link Detection (UDLD) on an individual interface or to prevent a fiber-optic interface from being enabled by the udld global configuration command, use the udld port command in interface configuration mode. To return to the udld global configuration command setting or to disable UDLD if entered for a nonfiber-optic port, use the no form of this command.
udld port [aggressive]
no udld port [aggressive]
aggressive |
(Optional) Enables UDLD in aggressive mode on the specified interface. |
On fiber-optic interfaces, UDLD is disabled and fiber-optic interfaces enable UDLD according to the state of the udld enable or udld aggressive global configuration command.
On nonfiber-optic interfaces, UDLD is disabled.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
A UDLD-capable port cannot detect a unidirectional link if it is connected to a UDLD-incapable port of another controller.
UDLD supports two modes of operation: normal (the default) and aggressive. In normal mode, UDLD detects unidirectional links due to misconnected interfaces on fiber-optic connections. In aggressive mode, UDLD also detects unidirectional links due to one-way traffic on fiber-optic and twisted-pair links and due to misconnected interfaces on fiber-optic links.
To enable UDLD in normal mode, use the udld port interface configuration command. To enable UDLD in aggressive mode, use the udld port aggressive interface configuration command.
Use the no udld port command on fiber-optic ports to return control of UDLD to the udld enable global configuration command or to disable UDLD on nonfiber-optic ports.
Use the udld port aggressive command on fiber-optic ports to override the setting of the udld enable or udld aggressive global configuration command. Use the no form on fiber-optic ports to remove this setting and to return control of UDLD enabling to the udld global configuration command or to disable UDLD on nonfiber-optic ports.
You can use these commands to reset an interface shut down by UDLD:
This example shows how to enable UDLD on an port:
Controller(config)# interface gigabitethernet6/0/1 Controller(config-if)# udld port
This example shows how to disable UDLD on a fiber-optic interface despite the setting of the udld global configuration command:
Controller(config)# interface gigabitethernet6/0/1 Controller(config-if)# no udld port
You can verify your settings by entering the show running-config or the show udld interface privileged EXEC command.
Command | Description |
Displays UDLD administrative and operational status for all ports or the specified port. | |
Enables aggressive or normal mode in UDLD or sets the configurable message timer time. | |
Resets all interfaces shut down by UDLD and permits traffic to pass through again. |
To reset all interfaces disabled by UniDirectional Link Detection (UDLD) and permit traffic to begin passing through them again (though other features, such as spanning tree, Port Aggregation Protocol (PAgP), and Dynamic Trunking Protocol (DTP) still have their normal effects, if enabled), use the udld reset command in privileged EXEC mode.
udld reset
This command has no arguments or keywords.
None
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS XE 3.2SE |
This command was introduced. |
If the interface configuration is still enabled for UDLD, these ports begin to run UDLD again and are disabled for the same reason if the problem has not been corrected.
This example shows how to reset all interfaces disabled by UDLD:
Controller# udld reset
1 ports shutdown by UDLD were reset.
Command | Description |
Displays UDLD administrative and operational status for all ports or the specified port. | |
Enables aggressive or normal mode in UDLD or sets the configurable message timer time. | |
Enables UDLD on an individual interface or prevents a fiber-optic interface from being enabled by the udld global configuration command. |