Configure EtherChannel on a Cisco Catalyst Switch with Cisco Network Assistant
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Introduction
This document explains how to setup EtherChannel between Cisco Catalyst
Switches with Cisco Network Assistant (CNA). This procedure applies to 2900XL,
2940, 2950, 2960, 2970, 3500XL, 3550, 3560, and 3750 model Catalyst
switches.
EtherChannel is a group of Fast Ethernet or Gigabit Ethernet ports that
acts as a single logical port for high-bandwidth connections between switches
or between switches and servers/routers. You can use it to increase the
bandwidth between the wiring closets and the data center, and you can deploy it
anywhere in the network where bottlenecks are likely to occur. If a port within
an EtherChannel fails, traffic previously carried over the failed port
transfers to the remaining ports within the EtherChannel. The ports which are
bundled must have the same speed, duplex mode, native VLAN, VLAN range, and
trunking status and type.
This diagram gives you an overview on how EtherChannel is bundled
between two switches, Catalysts 3550 and Catalyst 3560 in the network. In this
document, two Fast Ethernet ports from each of the switches are bundled into an
FEC.
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Requirements
To perform the steps described in this document, you need to have these
items:
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Configure EtherChannel for a Cisco Catalyst Switch
This document explains how to configure EtherChannel between Cisco
Catalyst Switches:
Connect Your PC to the Switch
Follow these steps to connect the PC to the Cisco Catalyst
Switch:
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Connect a straight-through Ethernet cable from the PC to an
available port on the Cisco Catalyst Switch.
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Ensure that your PC has an IP address that matches the switch IP
address. For example, if the IP address of the switch is 192.168.10.9,
configure the PC with an IP address between 192.168.10.10 and 192.168.10.254.
For more detailed instructions on how to configure an IP address on your PC,
refer to Configure an IP
Address on Your PC.
Create a Community
A community can contain up to 40 devices, which consists of Catalyst
switches, Cisco access routers, PIX Firewalls, and ASAs (Adaptive Security
Appliances). When you create a community, it allows you to configure
EtherChannel between two devices (switches) simultaneously.
Follow these steps to form a community between Catalyst 3550 and
Catalyst 3560 switches.
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To launch CNA, go to Start >
Programs > Cisco Network Assistant >
Cisco Network Assistant.
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When the Connect window opens, select
Create community and click Connect, to open
the create community window.
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Use the Create Community window to discover
devices that you can add to a community
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In the Name field, enter a name for the
community. The name can be up to 64 characters long. You can use the characters
A-Z, a-z, 0-9, - (hyphen), and _ (underscore).
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From the Discover field drop-down menu select
the option devices in an IP address range.
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In the Start IP Address: and End IP
Address: fields, enter the IP address range to discover the devices
and add to a community group.
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Click the Start button to start the discovery
process.
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Click Yes to accept the security certificate
alert.
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When prompted enter the Username and
Password of the devices which are being discovered in the
Authentication: Device window.
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Click Yes if you get another security certificate
alert while you discover multiple devices.
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When discovery begins, the Start button becomes a
Stop button. Click it any time when you want to interrupt the
discovery process.
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Find the rows in the Devices table for the devices
that you have discovered in the Create Community window. Check
the boxes at the left of the rows and click OK to add the
selected devices to the community and to close the window.
Note: You can select up to 40 devices, not counting access
points.
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If Network Assistant does not discover a device that you want in
your community, try step 3b again selecting a different
Discover option from the drop down menu with
a different Discover option. This table lists the
Discover options, explains what to enter in the list, and
describes what Network Assistant does in the Devices table.
Discovery Method
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What to Enter
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What Network Assistant Does
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A single device by IP address
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The IP address of a device that you want the Network
Assistant to discover
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Information about the discovered device
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Devices which uses a seed IP address
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A seed IP address—the IP address of a device with neighbors
that you want to add to your community
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Information about the device that you identified and about
the neighbors that Cisco Discovery Protocol discovered up to a hop count of 4
from the seed device.
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Devices on a subnet
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An IP address and a subnet mask that identify a subnet
whose devices you want to add to your community
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Information about the devices that it discovers on the
subnet
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Devices in an IP address range
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The start and end IP addresses whose range delimit the
devices that you want to add to your community
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Information about the devices that it discovers in the IP
address range
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The CNA screen appears and displays the topology view of the
devices discovered.
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Configure EtherChannel between Catalyst 3560 and Catalyst 3550 Switches
Follow these steps to configure EtherChannel between two Catalyst 3560
and 3550 switches.
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Click Configure > Ports >
EtherChannels on the feature bar.
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Select Catalyst 3560 (local switch) from the
Hostname list on which you want to configure EtherChannel
settings. The information in the Channel Groups area applies
to the selected device.
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Select one of these options from the Load Balance list:
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Source MAC address. The traffic distribution is
based on the source MAC address of the incoming packets. Packets from different
hosts use different ports in the channel; packets from the same host use the
same port in the channel.
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Destination MAC address. The traffic
distribution is based on the destination host MAC address of the incoming
packets. Packets which goes to the same destination are sent on the same port;
packets which goes to different destinations are sent on different ports in the
channel.
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Source-Destination MAC address. The traffic
distribution is based on both the source and destination MAC addresses of the
incoming packets. Use this forwarding method if, it is not clear whether
source-MAC or destination-MAC address forwarding is preferable on a switch.
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Source IP address. The traffic distribution is
based on the source IP address of the incoming packets. Packets from different
IP addresses use different ports in the channel; packets from the same IP
address use the same port in the channel.
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Destination IP address. The traffic distribution
is based on the destination IP address of the incoming packets. Packets sent to
the same destination IP address are sent on the same port in the channel;
packets sent to different destination IP addresses are sent on different ports
in the channel.
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Source-Destination IP address. The traffic
distribution is based on both the source and destination IP addresses of the
incoming packets. Use this forwarding method if, it is not clear whether
source-IP or destination-IP address forwarding is preferable on a switch.
For example if you want to load balance with Source MAC Address
only, select the option Source MAC Address. Your choice
applies to every port group that you create on the switch.
Note: All switches do not support all the load balancing techniques
stated above. Contact the
SMB
Technical Assistance Center (SMB TAC) for further assistance.
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Click Create tab.
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In the Create EtherChannel window, follow these
steps:
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To configure EtherChannel between the Catalyst 3560 and Catalyst
3550 switches simultaneously, select the remote device Catalyst
3550 switch from the Remote Device
list.
Note: Notice that the options for the remote device are the same as
those for the local device. When you select options for the local device, do
the same for the remote device.
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Next to the Remote Ports side of the window of
Catalyst 3550 switch, you can see the Catalyst 3550 switch ports that are
connected to the Catalyst 3560 switch ports.
Note: Notice that the options for the remote device are the same as
those for the local device. When you select options for the local device, do
the same for the remote device.
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In the Group field, enter the channel group
number. The number can range from 1-48. For example enter the value 1 in the
Group field for both local and remote device.
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Check the box next to In Group for each port
that you want to be a group member. As showed in the network diagram in the
Overview section, select ports Fa0/13 and
Fa0/14. These two ports Fa0/13 and Fa0/14 from each switch are bundled to form
a Fast EtherChannel.
Note: By default once you select the ports, the Mode
and Priority fields of the ports have the values
LACP and 32768 respectively. If you want to
change the Mode or Priority fields see steps 5e and 5f else go to 5g.
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Click in the Mode cells for the selected ports, and select one of
these values:
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LACP—The port can form a link aggregate and
initiate the channel. The aggregate is formed if the other end runs LACP in
LACP or LACP (Passive) mode. LACP mode is
similar to the PAgP mode of Desirable.
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LACP (Passive)—The port can understand LACP
packets but does not initiate the channel. It replies to a received LACP packet
to form the channel if the other end is in LACP mode.
LACP (Passive) mode is similar to the PAgP mode of
Auto.
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Desirable—The port initiates negotiations with
other ports which sends PAgP packets.
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Auto—The port responds to the PAgP packets it
receives but, does not initiate PAgP negotiations. This mode minimizes PAgP
transmissions. It is the default.
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Desirable non-silent—The same as
Desirable but, without support for connections to file servers
or packet analyzers.
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Auto non-silent—The same as
Auto but, without support for connections to file servers or
packet analyzers.
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On (No LACP)—The port does not use PAgP or
LACP. A usable EtherChannel only exists if the port group is connected to
another group in this mode.
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Click in the Priority cells for the selected ports and enter a
LACP priority if you do not want the default 32768. The port with the highest
priority sends the packets.
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Click OK to close the
window.
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The new port group appears in the EtherChannels
window. Click Apply.
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Verify the EtherChannel status next to the
Status field of the EtherChannels window. The
value In Use(Layer2) confirms that the EtherChannel has been
configured properly and active. Click OK to close the
window.
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Next Step
You have completed this procedure.
To make other changes to your switch, refer to
Switch
Support Page.
To configure other devices in your network, refer to the
Configuration
Overview Page.
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Troubleshoot the Procedure
This section provides information about common problems that you may
encounter. If this information does not solve your problem, contact the
SMB
Technical Assistance Center (SMB TAC) for assistance.
Problem
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Cause(s) and Suggested Solution(s)
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You connected a PC directly to the switch, but you are unable
to launch CNA.
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Ensure that the power-on self test (POST) is completed
successfully. The SYSTEM LED must be solid green.
After you connect the switch to the PC, you must wait for 30
seconds before you can try to connect. Wait for 30 seconds, and then try to
connect again.
Ensure that you use the correct cable. You must use a
straight-through cable, not a crossover cable. Refer to
Cable
Descriptions for more information.
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In Step 7 of the Configure EtherChannel
between Catalyst 3560 and Catalyst 3550 Switches section, the
EtherChannel status shows Down(Layer2) .
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EtherChannel or LACP may not be currently configured on the
remote switch or ports which needs to be bundled to form EtherChannel.
Ensure all the remote and local switch ports which needs to be
bundled to form EtherChannel are up by entering shut and then
no shut command under Interface configuration mode using
Command Line Interface.
Repeat the section Configure
EtherChannel between Catalyst 3560 and Catalyst 3550
Switches.
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Related Information
