To configure EtherChannel according to the topology diagram, please
follow the guide step by step.

To configure EtherChannel consistent with the topology diagram, please
follow the guide step by step.

Step 1: Configure basic configuration on the switch
a. assign hostname each switch supported the topology diagram

Step 1: Configure basic configuration on the switch a. assign hostname each switch supported the topology diagram

Switch>en
Switch#config t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#hostname S1
S1(config)#

Switch>en
Switch#config t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#hostname S2
S2(config)#

Switch>en
Switch#config t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#hostname S3
S3(config)#

b. Configure trunk port counting on the connection between device, S1, S2, and S3

S1
S1(config)#
S1(config)#int range g0/1 – 2
S1(config-if-range)#switchport mode trunk
S1(config-if-range)#

S1#config t
Enter configuration commands, one per line. End with CNTL/Z.
S1(config)#
S1(config)#int range fa0/21 – 22
S1(config-if-range)#switchport mode trunk
S1(config-if-range)#

S1(config-if-range)#do copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
S1(config-if-range)#

S2
S2(config)#int range gi0/1 – 2
S2(config-if-range)#switchport mode trunk
S2(config-if-range)#int range fa0/23 – 24
S2(config-if-range)#switchport mode trunk

S2(config-if-range)#
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/23, changed state to down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/23, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/24, changed state to down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/24, changed state to up

S2(config-if-range)#do copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
S2(config-if-range)#

S3
S3(config)#
S3(config)#
S3(config)#int range fa0/23 – 24
S3(config-if-range)#switchport mode trunk
S3(config-if-range)#int range fa0/21 – 22
S3(config-if-range)#switchport mode trunk
S3(config-if-range)#do copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
S3(config-if-range)#

Step 2: Configure port Channel 1

a. Show connectivity trunk link on port F0/22 and F0/21 between S1 and S3 by using the command
show interface trunk.

S1
S1>en
S1#show int trunk
Port Mode Encapsulation Status Native vlan
Fa0/21 on 802.1q trunking 1
Fa0/22 on 802.1q trunking 1
Gig0/1 on 802.1q trunking 1
Gig0/2 on 802.1q trunking 1

Port Vlans allowed on trunk
Fa0/21 1-1005
Fa0/22 1-1005
Gig0/1 1-1005
Gig0/2 1-1005

Port Vlans allowed and active in management domain
Fa0/21 1
Fa0/22 1
Gig0/1 1
Gig0/2 1

Port Vlans in spanning tree forwarding state and not pruned
Fa0/21 1
Fa0/22 none
Gig0/1 none
Gig0/2 none

S3
S3>en
S3#show int trunk
Port Mode Encapsulation Status Native VLAN
Fa0/21 on 802.1q trunking 1
Fa0/22 on 802.1q trunking 1
Fa0/23 on 802.1q trunking 1
Fa0/24 on 802.1q trunking 1

Port Vlans allowed on trunk
Fa0/21 1-1005
Fa0/22 1-1005
Fa0/23 1-1005
Fa0/24 1-1005

Port Vlans allowed and active in management domain
Fa0/21 1
Fa0/22 1
Fa0/23 1
Fa0/24 1

Port Vlans in spanning tree forwarding state and not pruned
Fa0/21 1
Fa0/22 1
Fa0/23 1
Fa0/24 1

b. On both switches, add ports F0/21 and F0/22 to Port Channel 1
with the channel-group 1 mode desirable command.

S1
S1#config t
Enter configuration commands, one per line. End with CNTL/Z.
S1(config)#
S1(config)#int range fa0/21 – 22
S1(config-if-range)#sh

S1(config-if-range)#
%LINK-5-CHANGED: Interface FastEthernet0/21, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/21, changed state to down

%LINK-5-CHANGED: Interface FastEthernet0/22, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/22, changed state to down

S1(config-if-range)#channel-group 1 mode desirable
S1(config-if-range)#
Creating a port-channel interface Port-channel 1
S1(config-if-range)#no sh

S1(config-if-range)#
%LINK-5-CHANGED: Interface FastEthernet0/21, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/21, changed state to up

%LINK-5-CHANGED: Interface FastEthernet0/22, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/22, changed state to up

S1(config-if-range)#

S3
S3(config)#int range fa0/21 – 22
S3(config-if-range)#sh

S3(config-if-range)#
%LINK-5-CHANGED: Interface FastEthernet0/21, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/21, changed state to down

%LINK-5-CHANGED: Interface FastEthernet0/22, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/22, changed state to down

S3(config-if-range)#channel-group 1 mode desirable
S3(config-if-range)#
Creating a port-channel interface Port-channel 1
S3(config-if-range)#no sh

c. Configure the logical interface to become a trunk by first entering the
interface port-channel number command on S1 & S3 and then the switchport mode trunk command.

S1(config)#
S1(config)#int port-channel 1
S1(config-if)#switchport mode trunk
S1(config-if)#

S3(config)#
S3(config)#int port-channel 1
S3(config-if)#switchport mode trunk
S3(config-if)#

Step 3: Verify port Channel 1 status on S1 & S3
To verify portchannel status using command show etherchannel summary

S1
S1(config-if)#do show etherchannel summary
Flags: D – down P – 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
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) PAgP Fa0/21(P) Fa0/22(P)
S1(config-if)#

S3
S3(config-if)#do show EtherChannel summary
Flags: D – down P – 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
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) PAgP Fa0/21(P) Fa0/22(P)
S3(config-if)#

b. If the EtherChannel does not come up, shut down the physical interfaces
on both ends of the EtherChannel and then bring them back up again.
Use command sh & no sh.

The show interfaces trunk and show spanning-tree commands also show the port
channel as one logical link.

S1
S1(config-if)#do show int trunk
Port Mode Encapsulation Status Native VLAN
Po1 on 802.1q trunking 1
Gig0/1 on 802.1q trunking 1
Gig0/2 on 802.1q trunking 1

Port Vlans allowed on trunk
Po1 1-1005
Gig0/1 1-1005
Gig0/2 1-1005

Port Vlans allowed and active in management domain
Po1 1
Gig0/1 1
Gig0/2 1

Port Vlans in spanning tree forwarding state and not pruned
Po1 1
Gig0/1 1
Gig0/2 1

S1(config-if)#

S1(config-if)#do show spanning-tree
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 32769
Address 0001.436E.8494
Cost 9
Port 27(Port-channel1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 000A.F313.2395
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 20

Interface Role Sts Cost Prio.Nbr Type

Gi0/2 Desg FWD 4 128.26 P2p
Gi0/1 Desg FWD 4 128.25 P2p
Po1 Root FWD 9 128.27 Shr

S1(config-if)#

Step 4: Configure Port Channel 2, between S1 & S2 on ports G0/1 and G0/2

S1
S1(config)#int range gi0/1 – 2
S1(config-if-range)#sh

S1(config-if-range)#
%LINK-5-CHANGED: Interface GigabitEthernet0/1, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/1, changed state to down

%LINK-5-CHANGED: Interface GigabitEthernet0/2, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/2, changed state to down

S1(config-if-range)#channel-group 2 mode active
S1(config-if-range)#
Creating a port-channel interface Port-channel 2

S1(config-if-range)#int port-channel 2
S1(config-if)#switchport mode trunk
S1(config-if)#

S2
S2(config)#int range gi0/1 – 2
S2(config-if-range)#sh

%LINK-5-CHANGED: Interface GigabitEthernet0/1, changed state to administratively down

%LINK-5-CHANGED: Interface GigabitEthernet0/2, changed state to administratively down
S2(config-if-range)#channel-group 2 mode active
S2(config-if-range)#
Creating a port-channel interface Port-channel 2

S2(config-if-range)#no sh

%LINK-5-CHANGED: Interface GigabitEthernet0/1, changed state to down

%LINK-5-CHANGED: Interface GigabitEthernet0/2, changed state to down
S2(config-if-range)#int port-channel 2
S2(config-if)#switchport mode trunk
S2(config-if)#

Step 5: Verify Port Channel 2 Status on S1

To verify port channel status use command show EtherChannel summary

S1(config-if)#do show EtherChannel summary
Flags: D – down P – 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
u – unsuitable for bundling
w – waiting to be aggregated
d – default port

Number of channel-groups in use: 2
Number of aggregators: 2

Group Port-channel Protocol Ports
——+————-+———–+———————————————-

1 Po1(SU) PAgP Fa0/21(P) Fa0/22(P)
2 Po2(SU) LACP Gig0/1(P) Gig0/2(P)
S1(config-if)#

Step 6: Configure Port Channel 3 on S2

S2(config)#int range fa0/23 – 24
S2(config-if-range)#sh

S2(config-if-range)#channel-group 3 mode passive
S2(config-if-range)#
Creating a port-channel interface Port-channel 3

S2(config-if-range)#no sh

S2(config-if-range)#int port-channel 3
S2(config-if)#switchport mode trunk
S2(config-if)#

b. Port Channel 2 is not operative because spanning tree protocol placed
some ports into blocking mode. Unfortunately, those ports were Gigabit ports.
To restore these ports, configure S1 to be the primary root for VLAN 1 or set the priority to 24576.

S1(config)# spanning-tree vlan 1 root primary

S1(config)# spanning-tree vlan 1 priority 24576

To configure EtherChannel according to the topology diagram, please
follow the guide step by step.

To configure EtherChannel consistent with the topology diagram, please
follow the guide step by step.

Step 1: Configure basic configuration on the switch
a. assign hostname each switch supported the topology diagram

Step 1: Configure basic configuration on the switch a. assign hostname each switch supported the topology diagram

Switch>en
Switch#config t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#hostname S1
S1(config)#

Switch>en
Switch#config t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#hostname S2
S2(config)#

Switch>en
Switch#config t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#hostname S3
S3(config)#

b. Configure trunk port counting on the connection between device, S1, S2, and S3

S1
S1(config)#
S1(config)#int range g0/1 – 2
S1(config-if-range)#switchport mode trunk
S1(config-if-range)#

S1#config t
Enter configuration commands, one per line. End with CNTL/Z.
S1(config)#
S1(config)#int range fa0/21 – 22
S1(config-if-range)#switchport mode trunk
S1(config-if-range)#

S1(config-if-range)#do copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
S1(config-if-range)#

S2
S2(config)#int range gi0/1 – 2
S2(config-if-range)#switchport mode trunk
S2(config-if-range)#int range fa0/23 – 24
S2(config-if-range)#switchport mode trunk

S2(config-if-range)#
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/23, changed state to down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/23, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/24, changed state to down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/24, changed state to up

S2(config-if-range)#do copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
S2(config-if-range)#

S3
S3(config)#
S3(config)#
S3(config)#int range fa0/23 – 24
S3(config-if-range)#switchport mode trunk
S3(config-if-range)#int range fa0/21 – 22
S3(config-if-range)#switchport mode trunk
S3(config-if-range)#do copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
S3(config-if-range)#

Step 2: Configure port Channel 1

a. Show connectivity trunk link on port F0/22 and F0/21 between S1 and S3 by using the command
show interface trunk.

S1
S1>en
S1#show int trunk
Port Mode Encapsulation Status Native vlan
Fa0/21 on 802.1q trunking 1
Fa0/22 on 802.1q trunking 1
Gig0/1 on 802.1q trunking 1
Gig0/2 on 802.1q trunking 1

Port Vlans allowed on trunk
Fa0/21 1-1005
Fa0/22 1-1005
Gig0/1 1-1005
Gig0/2 1-1005

Port Vlans allowed and active in management domain
Fa0/21 1
Fa0/22 1
Gig0/1 1
Gig0/2 1

Port Vlans in spanning tree forwarding state and not pruned
Fa0/21 1
Fa0/22 none
Gig0/1 none
Gig0/2 none

S3
S3>en
S3#show int trunk
Port Mode Encapsulation Status Native VLAN
Fa0/21 on 802.1q trunking 1
Fa0/22 on 802.1q trunking 1
Fa0/23 on 802.1q trunking 1
Fa0/24 on 802.1q trunking 1

Port Vlans allowed on trunk
Fa0/21 1-1005
Fa0/22 1-1005
Fa0/23 1-1005
Fa0/24 1-1005

Port Vlans allowed and active in management domain
Fa0/21 1
Fa0/22 1
Fa0/23 1
Fa0/24 1

Port Vlans in spanning tree forwarding state and not pruned
Fa0/21 1
Fa0/22 1
Fa0/23 1
Fa0/24 1

b. On both switches, add ports F0/21 and F0/22 to Port Channel 1
with the channel-group 1 mode desirable command.

S1
S1#config t
Enter configuration commands, one per line. End with CNTL/Z.
S1(config)#
S1(config)#int range fa0/21 – 22
S1(config-if-range)#sh

S1(config-if-range)#
%LINK-5-CHANGED: Interface FastEthernet0/21, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/21, changed state to down

%LINK-5-CHANGED: Interface FastEthernet0/22, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/22, changed state to down

S1(config-if-range)#channel-group 1 mode desirable
S1(config-if-range)#
Creating a port-channel interface Port-channel 1
S1(config-if-range)#no sh

S1(config-if-range)#
%LINK-5-CHANGED: Interface FastEthernet0/21, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/21, changed state to up

%LINK-5-CHANGED: Interface FastEthernet0/22, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/22, changed state to up

S1(config-if-range)#

S3
S3(config)#int range fa0/21 – 22
S3(config-if-range)#sh

S3(config-if-range)#
%LINK-5-CHANGED: Interface FastEthernet0/21, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/21, changed state to down

%LINK-5-CHANGED: Interface FastEthernet0/22, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/22, changed state to down

S3(config-if-range)#channel-group 1 mode desirable
S3(config-if-range)#
Creating a port-channel interface Port-channel 1
S3(config-if-range)#no sh

c. Configure the logical interface to become a trunk by first entering the
interface port-channel number command on S1 & S3 and then the switchport mode trunk command.

S1(config)#
S1(config)#int port-channel 1
S1(config-if)#switchport mode trunk
S1(config-if)#

S3(config)#
S3(config)#int port-channel 1
S3(config-if)#switchport mode trunk
S3(config-if)#

Step 3: Verify port Channel 1 status on S1 & S3
To verify portchannel status using command show etherchannel summary

S1
S1(config-if)#do show etherchannel summary
Flags: D – down P – 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
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) PAgP Fa0/21(P) Fa0/22(P)
S1(config-if)#

S3
S3(config-if)#do show EtherChannel summary
Flags: D – down P – 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
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) PAgP Fa0/21(P) Fa0/22(P)
S3(config-if)#

b. If the EtherChannel does not come up, shut down the physical interfaces
on both ends of the EtherChannel and then bring them back up again.
Use command sh & no sh.

The show interfaces trunk and show spanning-tree commands also show the port
channel as one logical link.

S1
S1(config-if)#do show int trunk
Port Mode Encapsulation Status Native VLAN
Po1 on 802.1q trunking 1
Gig0/1 on 802.1q trunking 1
Gig0/2 on 802.1q trunking 1

Port Vlans allowed on trunk
Po1 1-1005
Gig0/1 1-1005
Gig0/2 1-1005

Port Vlans allowed and active in management domain
Po1 1
Gig0/1 1
Gig0/2 1

Port Vlans in spanning tree forwarding state and not pruned
Po1 1
Gig0/1 1
Gig0/2 1

S1(config-if)#

S1(config-if)#do show spanning-tree
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 32769
Address 0001.436E.8494
Cost 9
Port 27(Port-channel1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 000A.F313.2395
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 20

Interface Role Sts Cost Prio.Nbr Type

Gi0/2 Desg FWD 4 128.26 P2p
Gi0/1 Desg FWD 4 128.25 P2p
Po1 Root FWD 9 128.27 Shr

S1(config-if)#

Step 4: Configure Port Channel 2, between S1 & S2 on ports G0/1 and G0/2

S1
S1(config)#int range gi0/1 – 2
S1(config-if-range)#sh

S1(config-if-range)#
%LINK-5-CHANGED: Interface GigabitEthernet0/1, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/1, changed state to down

%LINK-5-CHANGED: Interface GigabitEthernet0/2, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/2, changed state to down

S1(config-if-range)#channel-group 2 mode active
S1(config-if-range)#
Creating a port-channel interface Port-channel 2

S1(config-if-range)#int port-channel 2
S1(config-if)#switchport mode trunk
S1(config-if)#

S2
S2(config)#int range gi0/1 – 2
S2(config-if-range)#sh

%LINK-5-CHANGED: Interface GigabitEthernet0/1, changed state to administratively down

%LINK-5-CHANGED: Interface GigabitEthernet0/2, changed state to administratively down
S2(config-if-range)#channel-group 2 mode active
S2(config-if-range)#
Creating a port-channel interface Port-channel 2

S2(config-if-range)#no sh

%LINK-5-CHANGED: Interface GigabitEthernet0/1, changed state to down

%LINK-5-CHANGED: Interface GigabitEthernet0/2, changed state to down
S2(config-if-range)#int port-channel 2
S2(config-if)#switchport mode trunk
S2(config-if)#

Step 5: Verify Port Channel 2 Status on S1

To verify port channel status use command show EtherChannel summary

S1(config-if)#do show EtherChannel summary
Flags: D – down P – 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
u – unsuitable for bundling
w – waiting to be aggregated
d – default port

Number of channel-groups in use: 2
Number of aggregators: 2

Group Port-channel Protocol Ports
——+————-+———–+———————————————-

1 Po1(SU) PAgP Fa0/21(P) Fa0/22(P)
2 Po2(SU) LACP Gig0/1(P) Gig0/2(P)
S1(config-if)#

Step 6: Configure Port Channel 3 on S2

S2(config)#int range fa0/23 – 24
S2(config-if-range)#sh

S2(config-if-range)#channel-group 3 mode passive
S2(config-if-range)#
Creating a port-channel interface Port-channel 3

S2(config-if-range)#no sh

S2(config-if-range)#int port-channel 3
S2(config-if)#switchport mode trunk
S2(config-if)#

b. Port Channel 2 is not operative because spanning tree protocol placed
some ports into blocking mode. Unfortunately, those ports were Gigabit ports.
To restore these ports, configure S1 to be the primary root for VLAN 1 or set the priority to 24576.

S1(config)# spanning-tree vlan 1 root primary

S1(config)# spanning-tree vlan 1 priority 24576

To configure EtherChannel according to the topology diagram, please
follow the guide step by step.

Step 1: Configure basic configuration on the switch
a. assign hostname each switch based on the topology diagram

Step 1: Configure basic configuration on the switch a. assign hostname each switch based on the topology diagram

Switch>en
Switch#config t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#hostname S1
S1(config)#

Switch>en
Switch#config t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#hostname S2
S2(config)#

Switch>en
Switch#config t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#hostname S3
S3(config)#


b. Configure trunk port depending on the connection between device, S1, S2, and S3

S1

S1(config)#
S1(config)#int range g0/1 – 2
S1(config-if-range)#switchport mode trunk
S1(config-if-range)#

S1#config t
Enter configuration commands, one per line. End with CNTL/Z.
S1(config)#
S1(config)#int range fa0/21 – 22
S1(config-if-range)#switchport mode trunk
S1(config-if-range)#

S1(config-if-range)#do copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
S1(config-if-range)#

S2

S2(config)#int range gi0/1 – 2
S2(config-if-range)#switchport mode trunk
S2(config-if-range)#int range fa0/23 – 24
S2(config-if-range)#switchport mode trunk

S2(config-if-range)#
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/23, changed state to down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/23, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/24, changed state to down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/24, changed state to up

S2(config-if-range)#do copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
S2(config-if-range)#

S3

S3(config)#
S3(config)#
S3(config)#int range fa0/23 – 24
S3(config-if-range)#switchport mode trunk
S3(config-if-range)#int range fa0/21 – 22
S3(config-if-range)#switchport mode trunk
S3(config-if-range)#do copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
S3(config-if-range)#


Step 2: Configure port Channel 1

a. Show connectivity trunk link on port F0/22 and F0/21 between S1 and S3 by using the command
show interface trunk.

S1

S1>en
S1#show int trunk
Port Mode Encapsulation Status Native vlan
Fa0/21 on 802.1q trunking 1
Fa0/22 on 802.1q trunking 1
Gig0/1 on 802.1q trunking 1
Gig0/2 on 802.1q trunking 1

Port Vlans allowed on trunk
Fa0/21 1-1005
Fa0/22 1-1005
Gig0/1 1-1005
Gig0/2 1-1005

Port Vlans allowed and active in management domain
Fa0/21 1
Fa0/22 1
Gig0/1 1
Gig0/2 1

Port Vlans in spanning tree forwarding state and not pruned
Fa0/21 1
Fa0/22 none
Gig0/1 none
Gig0/2 none

S3

S3>en
S3#show int trunk
Port Mode Encapsulation Status Native VLAN
Fa0/21 on 802.1q trunking 1
Fa0/22 on 802.1q trunking 1
Fa0/23 on 802.1q trunking 1
Fa0/24 on 802.1q trunking 1

Port Vlans allowed on trunk
Fa0/21 1-1005
Fa0/22 1-1005
Fa0/23 1-1005
Fa0/24 1-1005

Port Vlans allowed and active in management domain
Fa0/21 1
Fa0/22 1
Fa0/23 1
Fa0/24 1

Port Vlans in spanning tree forwarding state and not pruned
Fa0/21 1
Fa0/22 1
Fa0/23 1
Fa0/24 1

b. On both switches, add ports F0/21 and F0/22 to Port Channel 1
with the channel-group 1 mode desirable command.

S1

S1#config t
Enter configuration commands, one per line. End with CNTL/Z.
S1(config)#
S1(config)#int range fa0/21 – 22
S1(config-if-range)#sh

S1(config-if-range)#
%LINK-5-CHANGED: Interface FastEthernet0/21, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/21, changed state to down

%LINK-5-CHANGED: Interface FastEthernet0/22, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/22, changed state to down

S1(config-if-range)#channel-group 1 mode desirable
S1(config-if-range)#
Creating a port-channel interface Port-channel 1
S1(config-if-range)#no sh

S1(config-if-range)#
%LINK-5-CHANGED: Interface FastEthernet0/21, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/21, changed state to up

%LINK-5-CHANGED: Interface FastEthernet0/22, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/22, changed state to up

S1(config-if-range)#

S3

S3(config)#int range fa0/21 – 22
S3(config-if-range)#sh

S3(config-if-range)#
%LINK-5-CHANGED: Interface FastEthernet0/21, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/21, changed state to down

%LINK-5-CHANGED: Interface FastEthernet0/22, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/22, changed state to down

S3(config-if-range)#channel-group 1 mode desirable
S3(config-if-range)#
Creating a port-channel interface Port-channel 1
S3(config-if-range)#no sh

c. Configure the logical interface to become a trunk by first entering the
interface port-channel number command on S1 & S3 and then the switchport mode trunk command.

S1(config)#
S1(config)#int port-channel 1
S1(config-if)#switchport mode trunk
S1(config-if)#

S3(config)#
S3(config)#int port-channel 1
S3(config-if)#switchport mode trunk
S3(config-if)#


Step 3: Verify port Channel 1 status on S1 & S3
To verify portchannel status using command show etherchannel summary

S1

S1(config-if)#do show etherchannel summary
Flags: D – down P – 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
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) PAgP Fa0/21(P) Fa0/22(P)
S1(config-if)#

S3

S3(config-if)#do show EtherChannel summary
Flags: D – down P – 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
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) PAgP Fa0/21(P) Fa0/22(P)
S3(config-if)#

b. If the EtherChannel does not come up, shut down the physical interfaces
on both ends of the EtherChannel and then bring them back up again.
Use command sh & no sh.

The show interfaces trunk and show spanning-tree commands also show the port
channel as one logical link.

S1

S1(config-if)#do show int trunk
Port Mode Encapsulation Status Native VLAN
Po1 on 802.1q trunking 1
Gig0/1 on 802.1q trunking 1
Gig0/2 on 802.1q trunking 1

Port Vlans allowed on trunk
Po1 1-1005
Gig0/1 1-1005
Gig0/2 1-1005

Port Vlans allowed and active in management domain
Po1 1
Gig0/1 1
Gig0/2 1

Port Vlans in spanning tree forwarding state and not pruned
Po1 1
Gig0/1 1
Gig0/2 1

S1(config-if)#

S1(config-if)#do show spanning-tree
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 32769
Address 0001.436E.8494
Cost 9
Port 27(Port-channel1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 000A.F313.2395
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 20

Interface Role Sts Cost Prio.Nbr Type


Gi0/2 Desg FWD 4 128.26 P2p
Gi0/1 Desg FWD 4 128.25 P2p
Po1 Root FWD 9 128.27 Shr

S1(config-if)#

Step 4: Configure Port Channel 2, between S1 & S2 on ports G0/1 and G0/2

S1

S1(config)#int range gi0/1 – 2
S1(config-if-range)#sh

S1(config-if-range)#
%LINK-5-CHANGED: Interface GigabitEthernet0/1, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/1, changed state to down

%LINK-5-CHANGED: Interface GigabitEthernet0/2, changed state to administratively down

%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/2, changed state to down

S1(config-if-range)#channel-group 2 mode active
S1(config-if-range)#
Creating a port-channel interface Port-channel 2

S1(config-if-range)#int port-channel 2
S1(config-if)#switchport mode trunk
S1(config-if)#

S2

S2(config)#int range gi0/1 – 2
S2(config-if-range)#sh

%LINK-5-CHANGED: Interface GigabitEthernet0/1, changed state to administratively down

%LINK-5-CHANGED: Interface GigabitEthernet0/2, changed state to administratively down
S2(config-if-range)#channel-group 2 mode active
S2(config-if-range)#
Creating a port-channel interface Port-channel 2

S2(config-if-range)#no sh

%LINK-5-CHANGED: Interface GigabitEthernet0/1, changed state to down

%LINK-5-CHANGED: Interface GigabitEthernet0/2, changed state to down
S2(config-if-range)#int port-channel 2
S2(config-if)#switchport mode trunk
S2(config-if)#


Step 5: Verify Port Channel 2 Status on S1

To verify port channel status use command show EtherChannel summary

S1(config-if)#do show EtherChannel summary
Flags: D – down P – 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
u – unsuitable for bundling
w – waiting to be aggregated
d – default port

Number of channel-groups in use: 2
Number of aggregators: 2

Group Port-channel Protocol Ports
——+————-+———–+———————————————-

1 Po1(SU) PAgP Fa0/21(P) Fa0/22(P)
2 Po2(SU) LACP Gig0/1(P) Gig0/2(P)
S1(config-if)#

Step 6: Configure Port Channel 3 on S2

S2(config)#int range fa0/23 – 24
S2(config-if-range)#sh

S2(config-if-range)#channel-group 3 mode passive
S2(config-if-range)#
Creating a port-channel interface Port-channel 3

S2(config-if-range)#no sh

S2(config-if-range)#int port-channel 3
S2(config-if)#switchport mode trunk
S2(config-if)#

b. Port Channel 2 is not operative because spanning tree protocol placed
some ports into blocking mode. Unfortunately, those ports were Gigabit ports.
To restore these ports, configure S1 to be the primary root for VLAN 1 or set the priority to 24576.

S1(config)# spanning-tree vlan 1 root primary

S1(config)# spanning-tree vlan 1 priority 24576

Lab file is taken from netacad.com

By Admin