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Lab Objective:

Learn how to configure port aggregation using Port Aggregation Protocol (PAgP).

Lab Purpose:

Collecting interfaces or ports into one big virtual interface is known as link aggregation, link teaming, NIC teaming, or port channeling. The interfaces in the bundle should usually share the same capacity, so you can’t bundle a 100 Mbps interface with a 1 Gbps interface to make it 1.1 Gbps, for example.

We will bundle some Cisco switch interfaces into a group using PAgP. This interface will create a port channel interface with a theoretical speed of 400 Mbps. If any of the interfaces in the bundle goes down, the traffic will be load-balanced over the remaining ports.

Lab Tool:

Packet Tracer

Lab Topology:

Please use the following topology to complete this lab exercise:

port aggregation

Lab Walkthrough:

Task 1:

Connect two switches together as per the diagram.

Task 2:

Configure the Ethernet interfaces on the switches. The ‘interface range’ command will save some time. Make them all access interfaces and put them all into VLAN 100. Here is how to do it on Switch0. Do the same on Switch1.

Switch(config)#hostname SW0

SW0(config)#interface range f0/1-4

SW0(config-if-range)#switchport mode access

SW0(config-if-range)#switchport access vlan 100

% Access VLAN does not exist. Creating vlan 100

SW0(config-if-range)#

Task 3:

Create a virtual interface and number it six using the command channel-group 6 mode desirable. At least one side of the link must be active in order for the group to come up. You can use auto on Switch1.

SW0(config-if-range)#channel-group 6 mode ?

active Enable LACP unconditionally

auto Enable PAgP only if a PAgP device is detected

desirable Enable PAgP unconditionally

on Enable Etherchannel only

passive Enable LACP only if a LACP device is detected

SW0(config-if-range)#channel-group 6 mode desirable

Creating a port-channel interface Port-channel 6

Sw1(config-if-range)#channel-group 6 mode auto

Task 4:

Check the interfaces on Switch 0 to see if the port channel interface has been created.

SW0#show ip interface brief

Interface IP-Address OK? Method Status Protocol

Port-channel6 unassigned YES manual up up

FastEthernet0/1 unassigned YES manual up up

FastEthernet0/2 unassigned YES manual up

[output truncated]

Task 5:

There are several commands you can issue to check the status of the port channel, including

SW0#show etherchannel ?

load-balance Load-balance/frame-distribution scheme among ports in

port-channel

port-channel Port-channel information

summary One-line summary per channel-group

<cr>

Notes:

The ports will load-balance traffic based on factors such as destination/source IP/MAC, etc. You can alter this behavior, but it’s beyond the scope of the exam.

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