Lab 4-7 – Configuring EtherChannel Utilizing LACP

In this lab you will learn how to configure a dynamic EtherChannel using the IEEE Standard protocol; Link Aggregation Control Protocol, also known as LACP.

Real World Application & Core Knowledge

In the world of EtherChannel technology there are two types of dynamic channel-group protocols, Port Aggregation Protocol (PAgP) which is a Cisco Proprietary protocol and Link Aggregation Control Protocol (LACP) which is the IEEE standard.

LACP uses two types of port modes; active and passive. LACP active mode unconditionally forms a LACP dynamic ether-channel whereas passive will only accept LACP negotiation attempts from a device set to active.

In this lab you will familiarize yourself with the following commands;

channel-group # mode active – This command when executed in interface configuration mode sets the channel-group number and LACP mode to aggressively attempt to form a LACP EtherChannel. If negotiations fail, the EtherChannel will not pass traffic.

channel-group # mode passive – This command when executed in interface configuration mode sets the channel-group number and LACP mode to listen for LACP packets but not aggressively and unconditionally form an EtherChannel using LACP.

show etherchannel summary – This command when executed from user or privileged mode will display a summary of local EtherChannel(s) properties such as the channel-group number, ports in the channel group, and the role the ports the play.

show etherchannel detail – This command when executed from user or privileged mode will display detailed information relating to the EtherChannel(s) local to the device.

Lab Prerequisites

• Establish a console session with devices R1, R2, SW1 and SW2 than configure the devices respected hostname(s).
• Configure VLAN 10 on both SW1 and SW2 and assign R1 and R2′s switch ports to VLAN 10.
• Assign the IP address 10.1.1.1/24 to R1′s FastEthernet0/0 interface and 10.1.1.2/24 to R2′s FastEthernet0/1 interface.

Lab Objectives

• Configure SW1′s Fa0/10, Fa0/11 and Fa0/12 interfaces to aggressively attempt to form a LACP EtherChannel.
• Configure SW2′s Fa0/10, Fa0/11 and Fa0/12 interfaces to form a PAgP EtherChannel only when a device attempts to negotiate a LACP EtherChannel only.
• Verify that interfaces Fa0/10, Fa0/11 and Fa0/12 on SW1 formed a LACP EtherChannel correctly.
• Verify IP communication over the newly formed LACP Ether-Channel by pinging R2′s Fa0/1 IP Address from R1.

Lab Instruction

Step 1 . – Configure SW1′s Fa0/10, Fa0/11 and Fa0/12 interfaces to aggressively attempt to form a LACP EtherChannel.

For this you’ll use the channel-group # mode active command in interface or interface range configuration mode as shown below;

SW1 con0 is now available

Press RETURN to get started.

SW1>enable
SW1#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
SW1(config)#interface range f0/10 - 12
SW1(config-if-range)#no shut
SW1(config-if-range)#channel-group 1 mode active
Creating a port-channel interface Port-channel 1
SW1(config-if-range)#end
SW1#

Step 2. – Configure SW2′s Fa0/10, Fa0/11 and Fa0/12 interfaces to form a PAgP EtherChannel only when a device attempts to negotiate a LACP EtherChannel only.

For this you’ll use the channel-group # mode passive command in interface or interface range configuration mode as shown below;

SW2 con0 is now available

Press RETURN to get started.

SW2>enable
SW2#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
SW2(config)#interface range f0/10 - 12
SW2(config-if-range)#no shut
SW2(config-if-range)#channel-group 1 mode passive
Creating a port-channel interface Port-channel 1
SW2(config-if-range)#end
SW2#

Step 3. – Verify that interfaces Fa0/10, Fa0/11 and Fa0/12 on SW1 formed a LACP EtherChannel correctly.

To verify the EtherChannel LACP configuration you can use either the show etherchannel summary or show etherchannel detail command in user or privileged mode as shown below;

SW1#show etherchannel summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

Number of channel-groups in use: 1
Number of aggregators:           1

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------
1      Po1(SU)         LACP      Fa0/10(P)   Fa0/11(P)   Fa0/12(P)   

SW1#

Step 4. – Verify IP communication over the newly formed LACP Ether-Channel by pinging R2′s Fa0/1 IP Address from R1 as shown below;

R1#ping 10.1.1.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.2, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 1/2/4 ms
R1#