Etherchannel using LACP

[Sukanta Biswas]

Hello,

Could anyone please explain me whether I can create a port channel using LACP with two different ports from two different switches. The senario is below

i want to connect two servers (with daul NIC). lets say

switch_1 (port g0/5) to NIC_1 of server_1

switch_2 (port g0/5) to NIC_1 of server_2

switch_1 (port g0/7) to NIC_2 of server_1

switch_2 (port g0/7) to NIC_2 of server_2

please note that the switches (3550) are not stacked. Any suggestions/advice would be greatly appreciated.

Rgds

Sukanta

[Latchum Naidu]

Hi Sukanta,

Yes, you can create port channel by using LACP between two different switches.
You can connect your servers two NIC's to switch and assign channel-group in this way you can have redundancy and load balance.

Please see the below link for more information.
http://www.cisco.com/en/US/tech/tk389/tk213/technologies_configuration_example09186a0080094470.shtml

Please rate the helpfull posts.
Regards,
Naidu.

[Sukanta Biswas]

Hi Naidu,

thank you so much for your prompt response. But I am trying to create a channel-group like below

switch_1 (g0/5) and Switch_2 (g0/5)------- one channel group

switch_1 (g0/7) and switch_2 (g0/7)------- another channel group

or is there any other best way i can create two channel group for load balance & redundancy purpose?

Much appreciated any advise.

Rgds

sukanta

[Antonio Knox]

You can create channel between two ports on different switches, but you cannot use two switches to configure a single etherchannel to one server.  This configuration you seek to make is only possible if you are running Cisco VSS (Virtual Switching System).  However, using your example:

switch_1 (port g0/5) to NIC_1 of server_1

switch_1 (port g0/7) to NIC_2 of server_1

switch_2 (port g0/5) to NIC_1 of server_2

switch_2 (port g0/7) to NIC_2 of server_2

This appears to be a reasonable configuration.  I assume you want to implement ehterchannel with added redundancy across the switches.  Is this the reason you want to make this configuration?

Message was edited by: Antonio Knox

[Sukanta Biswas]

Hi Antonio,

yes, you are right. i think, i mistyped the port. I exactly want to setup channel group as you mentioned considering redundancy. I would also want to set this layer 2 channel group.

Any suggestions, greatly appreciated.

[Antonio Knox · Accepted solution]

You would only be able to achieve what you seek by teaming the ports on the server side and connecting the the ports across the two switches.

Example:

Servers side

VIP: 10.1.1.7

NIC_1  -->  Switch 1

NIC_2  -->  Switch 2

You could make it work this way, but limitations of non-VSS switches will not allow this configuration via etherchannel.

[Thotsaphon Lueangwattanaphong]

Hi Sukata,

       I should not do that. Let me explain what it should be.

Server: Using LACP means that NIC1 and NIC2 should be Active/Active.

Switch: C3550 has no idea about LACP configuration on other switch.

Solution: Configure the Server to run Active/Standby aka fault tolerance. No need to configure anything on C3550.

Optional , Server : Active/Active mode.

1. Terminate Nic1 and Nic2 on the switch and then use LACP on both sides.

2. Using Cross-Stack Etherchannel on C3750 Stack. Two switches can be used.

3. Using VSS on Cisco 6500 Switch. Two switches can be used.

HTH,

Toshi