Disabling IP Learning in FlexConnect Mode

Information About Disabling IP Learning in FlexConnect Mode

In FlexConnect local switching scenarios, where clients from the same sites may share the same address range, there is a possibility of multiple clients being allocated or registered with the same IP address. The controller receives IP address information from the AP, and if more than one client attempts to use the same IP address, the controller discards the last device trying to register an already-used address as an IP theft event, potentially resulting in client exclusion.

The Disabling IP learning in FlexConnect mode feature utilizes the no ip mac-binding command to ensure that no device tracking is done for clients, thus preventing the IP theft error.


Note


  • This feature is applicable only for IPv4 addresses.

  • Configuring ip overlap in FlexConnect Profile assists overlapping IP address support for clients across different sites in FlexConnect local switching.


Restrictions for Disabling IP Learning in FlexConnect Mode

  • The wireless client ip deauthenticate command works by referring to the IP table binding entries directly. It does not work for client whose IPs are not learnt.

  • Overlapping IP addresses within a single site tag and across different site tags require different settings. Furthermore, if a single site tag contains overlapping IP addresses, L3 web authentication is necessary. However, L3 web authentication relies on IP addresses, and ensuring the uniqueness of IP addresses cannot be guaranteed, making this combination incorrect.

  • When IP Source Guard (IPSG) is enabled and multiple binding information is sent with the same IP and preference level (such as DHCP, ARP, and so on) to CPP, the CPP starts to ignore the later bindings after the first binding creation. Hence, you should not configure IPSG and disable IP MAC binding together. If IPSG and no ip mac-binding are configured together then IPSG does not work.

Disabling IP Learning in FlexConnect Mode (CLI)

Procedure

  Command or Action Purpose

Step 1

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 2

wireless profile policy profile-policy-name

Example:

Device(config)# wireless profile policy test-profile-policy

Configures the wireless profile policy.

Step 3

shutdown

Example:

Device(config-wireless-policy)# shutdown

Disables the wireless policy profile.

Note

 

Disabling policy profile results in associated AP and client to rejoin.

Step 4

no ip mac-binding

Example:

Device(config-wireless-policy)# no ip mac-binding

Disables IP learning in FlexConnect mode.

Step 5

no shutdown

Example:

Device(config-wireless-policy)# no shutdown

Enables the wireless policy profile.

Step 6

exit

Example:

Device(config-wireless-policy)# exit

Returns to privileged EXEC mode.

Verifying MAC Entries from Database

To verify the MAC details from database, use the following command:


Device# show wireless device-tracking database mac
MAC VLAN IF-HDL IP
--------------------------------------------------------------------------------------------------
6c96.cff2.889a 64 0x90000008 9.9.64.175