L3 EtherChannel 1

Layer 3 switches, SVIs, routed ports, and L3 EtherChannels. Those topics alone make this lab fairly advanced for CCNA prep, not to mention that the L3 EtherChannel and routed ports are new to CCNA for this latest (2016) version of the exams. Today’s lab focuses on the L3 EtherChannel, but also gives you a chance to configure the rest of the features in the initial list as well.

Requirements

In this lab, you will add configuration to distribution switches Dist1 and Dist2. These two layer 3 switches will route packets for several subnets. Dist1 connects to the subnets supported by VLANs 10 and 20, while Dist2 connects to the subnets supported by VLANs 30 and 40. The two distribution switches connect with a layer 3 EtherChannel with two links.

Your job: configure the SVIs (VLAN interfaces) necessary for routing for the connected subnets on the access VLANs. The IP addresses on these SVIs will be used by the PCs in the network as their default gateway IP addresses. Then configure the layer 3 EtherChannel between the switches as well, providing a layer 3 link between the two distribution switches, so that they can route packets to each other.

This lab begins with several key features pre-configured. Make sure to pay close attention to the initial configurations to get your bearings before starting to do the lab. These items are preconfigured:

• The links connecting the Access switches with their Distribution switches are preconfigured as static trunks using 802.1q encapsulation.
• The access and distribution switches have been pre-configured with the VLAN IDs listed in the figure.
• All interfaces shown in the figure have been administratively enabled.
• Layer 3 switches Dist1 and Dist2 have been pre-configured with EIGRP, so that once the lab has been configured, Dist1 and Dist2 will exchange IPv4 routes.

The following list details your work for this lab:

• Configure Layer 3 switching with SVIs on the two distribution switches as follows:
  • Switch Dist1 routes for VLANs 10 and 20
  • Switch Dist2 routes for VLANs 30 and 40
• Configure a layer 3 EtherChannel for the two links between switches Dist1 and Dist2 so that IPv4 packets can be routed between the two switches, as follows:
  • Configure the two links between the distribution switches as a static layer 3 EtherChannel with portchannel interface number 10.
  • Make the EtherChannel a routed port instead of a switch port.
  • Configure the IP addresses per the figure for the PortChannel interface

Figure 1: Switch Square w/L3 EtherChannel Topology

Initial Configuration

Examples 1, 2, 3 and 4 shows the beginning configuration state of Dist1, Dist2, Access1 and Access2.

Example 1: Dist1 Config

hostname Dist1
!
interface GigabitEthernet0/1
 no shutdown
!
interface GigabitEthernet0/2
 no shutdown
!
interface GigabitEthernet0/3
 no shutdown
 switchport trunk encapsulation dot1q
 switchport mode trunk
!
router eigrp 10
 network 0.0.0.0

Example 2: Dist2 Config

hostname Dist1
!
interface GigabitEthernet0/1
 no shutdown
!
interface GigabitEthernet0/2
 no shutdown
!
interface GigabitEthernet0/3
 no shutdown
 switchport trunk encapsulation dot1q
 switchport mode trunk
!
router eigrp 10
 network 0.0.0.0

Example 3: Access1 Config

hostname Access1
!
vlan 10,20
!
interface GigabitEthernet0/1
 no shutdown
 switchport trunk encapsulation dot1q
 switchport mode trunk
!
interface GigabitEthernet0/2
 no shutdown
 switchport access vlan 10
!
interface GigabitEthernet0/3
 no shutdown
 switchport access vlan 20

Example 4: Access2 Config

hostname Access2
!
vlan 10,20
!
interface GigabitEthernet0/1
 no shutdown
 switchport trunk encapsulation dot1q
 switchport mode trunk
!
interface GigabitEthernet0/2
 no shutdown
 switchport access vlan 30
!
interface GigabitEthernet0/3
 no shutdown
 switchport access vlan 40

Answer on Paper, or Maybe Test in Lab

Next, write your answer on paper. Or if you have some real gear, or other tools, configure the lab with those tools.

To test your solution, if you happen to try it real gear, you can check using a couple of different commands. On the distribution switches check that the VLANs have been created by using the show vlan brief and show interfaces interface switchport command, then check that the VLAN interfaces were configured with the show ip interfaces brief and/or show running-config commands. Then check that the trunks are operational using the show interfaces trunk command.

For the layer 3 and layer 3 specifics, you should check on the L3 EtherChannel, the SVIs, and make sure EIGRP is working. Verify the state of the L3 EtherChannel using the show etherchannel summary command and check the port channel interface using the show interfaces port-channel10 command. The show interfaces status command should like the physical ports in the channel, as well as interface portchannel10, as a routed port rather than being assigned to a VLAN. Also, each switch should list three connected IPv4 routes in the output of the show ip route command.

Do this Lab with Cisco’s VIRL

You can do these labs on paper and still get a lot out of the lab. As an extra help, we have added files for the Virtual Internet Routing Lab (VIRL) software as well. The .VIRL file found here is a file that when used with VIRL will load a lab topology similar to this lab’s topology, with the initial configuration shown in the lab as well. This section lists any differences between the lab exercise and the .VIRL file’s topology and configuration.

Download this lab’s VIRL file!

The virl topology matches this lab topology exactly. The host info does as well.

Host device info:

This table lists host information pre-configured in VIRL, information that might not be required by the lab but may be useful to you.

Handy Host Commands:

To see PC IP address: ifconfig eth1

Ping example: ping -c 4 10.1.1.1

Trace example: tracepath 10.1.1.1

To connect to another node within the topology: telnet 10.1.1.1