CAPWAP Link Aggregation Support

CAPWAP LAG support

A CAPWAP LAG support feature is a controller-access point connectivity mechanism that

  • enables link aggregation of controller ports.

  • allows automatic failover of traffic if a port fails, and

  • simplifies controller configuration by removing the requirement to configure primary and secondary ports for each interface.

Link aggregation ensures that traffic is redirected automatically to a functioning port if one controler port fails. With at least one controller port operating, network connectivity is maintained, APs stay connected and wireless clients remain operational.

CAPWAP (Control and Provisioning of Wireless Access Points) is a protocol that manages communication between wireless LAN controllers and access points.

Link Aggregation refers to using multiple network connections in parallel to increase throughput and provide redundancy.

Supported models

The CAPWAP LAG support feature applies to APs with multiple Ethernet ports for CAPWAP.

  • 11AC APs with dual Ethernet ports require CAPWAP AP LAG support for their data channels.

  • By default, the second port on Cisco Aironet 1850, 2800, and 3800 Series APs is used for link aggregation. If you disable LAG, you can use the LAG port as an RLAN port.

These APs use LAG port as an RLAN (Remote LAN) port:

  • Cisco Aironet 1852E Access Point

  • Cisco Aironet 1852I Access Point

  • Cisco Aironet 2802E Access Point

  • Cisco Aironet 2802I Access Point

  • Cisco Aironet 3802E Access Point

  • Cisco Aironet 3802I Access Point

  • Cisco Aironet 3802P Access Point

Restrictions for CAPWAP LAG support

Ensure these requirements are met when using CAPWAP LAG support.

  • APs must be specifically enabled for CAPWAP AP LAG support.

  • CAPWAP data does not support IPv6.

  • Do not enable Datagram Transport Layer Security (DTLS) when you enable LAG.

  • CAPWAP LAG does not work with APs behind Network Address Translation (NAT) or Port Address Translation (PAT).

Enable CAPWAP LAG support on controller (GUI)

Enable LAG support for APs using the controller GUI.

Procedure

Step 1

Choose Configuration > Wireless > Wireless Global.

Step 2

Check the AP LAG Mode check box.

Step 3

Click Apply.

Enable CAPWAP LAG support on controller (CLI)

Enable LAG support for all APs on the controller using CAPWAP.

Procedure

Step 1

Enter the global configuration mode.

Example:

Device# configure terminal

Step 2

Enable CAPWAP LAG support on the controller.

Example:

Device(config)# ap lag support

Note

 

After executing this command, this warning statement is displayed:

Changing the lag support will cause all the APs to disconnect. Thus, all APs with LAG capability reboots and joins the enabled CAPWAP LAG.

Step 3

Returns to privileged EXEC mode. Alternatively, you can also press Ctrl-Z to exit global configuration mode.

Example:

Device(config)# end

Enable and disable CAPWAP LAG globally on controller

If the CAPWAP LAG is enabled globally on the controller, these events occur:

  • The AP joins the controller.

  • The AP exchanges its CAPWAP support.

  • LAG mode starts, if LAG is enabled on AP.

If the CAPWAP LAG is disabled globally on the controller, these events occur:

  • The AP joins the controller.

  • The AP exchanges its CAPWAP support.

  • The AP receives the LAG configuration if LAG is already enabled on the AP.

  • The AP reboots.

  • The AP joins again with LAG disabled.

Enable CAPWAP LAG for an AP profile (GUI)

Enable LAG mode for a CAPWAP AP profile to improve reliability and throughput using GUI.

Procedure

Step 1

Choose Configuration > Tags (and) Profiles > AP Join.

Step 2

Click Add.

Step 3

Under the General tab, enter the Name of the AP Profile and check the LAG Mode check box to set the CAPWAP LAG for the AP profile.

Step 4

Click Apply to Device.

Enable CAPWAP LAG for an AP profile (CLI)

Enable CAPWAP LAG on an AP profile to improve data throughput and provide redundancy for associated APs.

Procedure

Step 1

Enter the global configuration mode.

Example:

Device# configure terminal

Step 2

Configure an AP profile and enter the AP profile configuration mode. ap profile ap-profile .

Example:

Device(config)# ap profile xyz-ap-profile

Note

 

When you delete a named profile, the APs associated with that profile do not revert to the default profile.

Step 3

Enable CAPWAP LAG for an AP profile.

Example:

Device(config-ap-profile)# lag

Step 4

Exit configuration mode and return to privileged EXEC mode.

Example:

Device(config-ap-profile)# end

Disable CAPWAP LAG for an AP profile (CLI)

Disable CAPWAP LAG for a specified AP profile using commands.

Procedure

Step 1

Enter the global configuration mode.

Example:

Device# configure terminal

Step 2

Configure an AP profile and enter the AP profile configuration mode.

Example:

Device(config)# ap profile xyz-ap-profile

Note

 

When you delete a named profile, the APs associated with that profile do not revert to the default profile.

Step 3

Disable CAPWAP LAG for an AP profile.

Example:

Device(config-ap-profile)# no lag

Step 4

Exit configuration mode and return to privileged EXEC mode.

Example:

Device(config-ap-profile)# end

Disable CAPWAP LAG support on controller

Disable LAG support for the CAPWAP protocol using commands.

Procedure

Step 1

Enter the global configuration mode.

Example:

Device# configure terminal

Step 2

Disable CAPWAP LAG support on the controller .

Example:

Device(config)# no ap lag support

Note

 

All APs with LAG capability reboots and joins the disabled CAPWAP LAG.

Step 3

Exit configuration mode and return to the privileged EXEC mode.

Example:

Device(config)# end

Verify CAPWAP LAG support configurations

To verify the global LAG status for all Cisco APs, use the command:

Device# show ap lag-mode

AP Lag-Mode Support Enabled

To verify the AP LAG configuration status, use the command:

Device# show ap name config general

Cisco AP Identifier : 0008.3291.6360
Country Code : US
Regulatory Domain Allowed by Country : 802.11bg:-A 802.11a:-AB
AP Country Code : US - United States
::
AP Lag Configuration Status : Enabled/Disabled
Has AP negotiated lag based on AP capability and per AP config