Examkin

Question

Difficulty: MediumWLAN Infrastructure Connections and LAG

A network engineer needs to configure link aggregation (LAG) on a Cisco Catalyst switch connected to a Cisco AireOS Wireless LAN Controller (WLC). Arrange the following configuration steps in the correct logical order from first to last to ensure a functional static EtherChannel interface on the switch.

  1. 1Create and enter interface configuration mode for the logical port-channel interface.
  2. 2Configure switchport trunking encapsulation, trunk mode, and allowed VLANs on the port-channel interface.
  3. 3Select the range of physical member interfaces connected to the WLC distribution ports.
  4. 4Bind the physical member interfaces to the port-channel using channel-group mode on.

Answer

The correct order of steps is: 1. Create and enter interface configuration mode for the logical port-channel interface. 2. Configure switchport trunking encapsulation, trunk mode, and allowed VLANs on the port-channel interface. 3. Select the range of physical member interfaces connected to the WLC distribution ports. 4. Bind the physical member interfaces to the port-channel using channel-group mode on.
The correct operational sequence begins by creating the logical port-channel interface and setting its trunking and VLAN parameters. Next, the network engineer selects the physical switch interfaces connected to the controller's distribution ports and assigns them to the channel group using 'mode on'. Static aggregation is required because AireOS WLCs use unnegotiated bundle distribution across all active ports.

Step-by-Step Solution

1
Create the logical port-channel interface on the Catalyst switch.
The port-channel interface (e.g., interface Port-channel 1) is instantiated.
Establishing the logical bundle interface first provides a central point to apply trunking properties.
2
Apply 'switchport mode trunk' and allowed VLAN commands to the port-channel interface.
The logical interface is configured as an 802.1Q trunk carrying required WLAN management and data VLANs.
Applying configurations to the port-channel interface prevents port inconsistency errors across member links.
3
Enter interface range mode for the physical switch ports connecting to the WLC.
Physical ports (e.g., interface range GigabitEthernet1/0/1 - 2) are selected.
Physical interface mode is needed to assign the specific physical links into the aggregated bundle.
4
Issue the 'channel-group 1 mode on' command on the physical interfaces.
Physical interfaces join the port-channel as static EtherChannel members.
Cisco AireOS Wireless LAN Controllers do not negotiate LACP or PAgP control frames; the switch ports must use static channel mode 'on'.

Key Concept

Switch EtherChannel Configuration Sequence for AireOS WLC Link Aggregation
Estimated Time:1m 30s
Rate this question

Topics

WLAN Infrastructure Connections and LAG

More questions from this topic