Hi Istvan,

Ports Gigabit2/11, Gigabit2/12, Gigabit2/13 and Gigabit2/14 will be the ones being used for this etherchannel.

If LACP is the best language they can talk, then LACP it is.

Basically I need any VLAN to traverse this link, so I assume the link has to be a trunk.

I've read that each individual port should be setup as 1000 Mbps-full duplex.

What will be the correct setup for the etherchannel so that any VLANs can go thru it because there will be lots of blade servers that will be isolated on their own VLANs.

thanks in advance

Hi Angel,

As I mentioned, I can make the config for you for the Cisco switch:

conf t

port-channel load-balance {load-balance method}

lacp system-priority 100

interface range gig2/11 - 14

speed nonegotiate

switchport

switchport mode trunk

switchport trunk encapsulation dot1q

switchport trunk allowed vlan all

switchport trunk native vlan 1

channel-protocol lacp

channel-group 1 mode active

The load-balance method depends on your traffic. Please read more about it on the link here:

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.1/8aew/configuration/guide/channel.html

Click on the "Configuring EtherChannel Load Balancing" link.

Load balancing can be based on the mac-addresses, ip addresses (on 6500 and 4500 switches on port numbers as well).

Cheers:

Istvan

Istvan, great stuff. I will go ahead and get this configure at the 4506.

I am still digging for configuration help for the Nortel switch

I will post back.. but if anyone has some help with regards to configuring the nortel switch to talk to the 4506, that will be great

thanks in advance

Hi Istvan,

the statement "speed nonegotiate" didn't work.

What was this statement intended for?

I read a cisco document and it mentions something like "switchport nonegotiate". Is this the same thing?

Hi Angel,

This command may not work for some IOS releases.

It is intended to set the values to the default speed of 1000 Mbps and full duplex.

Use the "speed 1000" command instead, if your interfaces aren't set to that speed.

Gig interfaces should be full-duplex.

You can check it with the "show interface gig2/11" etc. command.

The "switchport nonegotiate" may also be useful. It disables DTP trunking negotiation. The Nortel switch doesn't support DTP, I suppose.

Cheers:

Istvan

Yes, just finished reading that the nortel switch doesnt support DTP.

I have set the load-balance method to "port-channel load-balance src-dst-ip" although I havent found any info on that in the nortel documentation, so hopefully this is supported.

The channel-protocol I will set to LACP as I've read nortel does support this. So basically I am done in the cisco 4506 and I am now setting up the nortel switch. Im close to do the first test.

Another big question.... currently, the 4 physical cables connecting the Nortel 6-port switch to the Cisco switch are straigh-thru cable. I've read that it is best to use cross-overs.... will this be a problem?

thanks for all the help Istvan

Hi Istvan,

I got my 4-port etherchannel working! It is communicating with the nortel switch and and my PCs behind the 4506 are happily talking to the servers behind the Nortel switch (the blades inside the IBM BladeCenter)

What I need to do now is check if all the 4 gigabit ports in the channel are indeed being used. How do I check this?

Here is my etherchannel config:

!

interface Port-channel1

description BLADECENTER_01

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1,50,99,150

switchport mode trunk

switchport nonegotiate

!

!

interface GigabitEthernet2/11

description BLADECENTER_01 --- Ethernet Switch Module 1 (Bay 1)

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1,50,99,150

switchport mode trunk

switchport nonegotiate

speed 1000

duplex full

channel-group 1 mode on

!

interface GigabitEthernet2/12

description BLADECENTER_01 --- Ethernet Switch Module 1 (Bay 1)

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1,50,99,150

switchport mode trunk

switchport nonegotiate

speed 1000

duplex full

channel-group 1 mode on

!

interface GigabitEthernet2/13

description BLADECENTER_01 --- Ethernet Switch Module 1 (Bay 1)

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1,50,99,150

switchport mode trunk

switchport nonegotiate

speed 1000

duplex full

channel-group 1 mode on

!

interface GigabitEthernet2/14

description BLADECENTER_01 --- Ethernet Switch Module 1 (Bay 1)

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1,50,99,150

switchport mode trunk

switchport nonegotiate

speed 1000

duplex full

channel-group 1 mode on

!

Also let me know if this looks pretty to you and if there is anything that needs work.

thanks in advance

Hi Angel,

I'm really happy your etherchannel is working.

You can check the traffic on all 4 Gig ports by issuing the "show interface Gig2/x" command.

In the output you will see the input and output traffic among other data, for the particular interface.

Please note, that the src-dst-ip etherchannel load balancing on 4 links works the following way:

It calculates the link to be used for the traffic by calcuating a XOR value of the last 2 bits of the source and destination ip addresses.

example:

source ip 192.168.1.1 (last 2 bits of the address: 01)

destination ip: 10.1.1.2 (last 2 bits of the address: 10)

link to be used within the channel: 01 XOR 10 = 11, that is 3.

This means that traffic between the same 2 nodes will always go through the same link within the channel in one direction.

If you have several sources and/or destinations with different ip addresses, then you will have traffics distributed among the links.

By checking the traffic within the link as above stated, you can play around with the load balancing method to achieve a more or less even distribution among the links.

Note also, that you have to set the load balancing method on both switches, because load balancing will affect the transmitted traffic only.

This way you may get different distribution of traffic in one direction and different traffic distribution in the other direction.

Cheers:

Istvan

Hi Angel,

In the morning rush I forgot to mention a very simple way to check load balanced traffic on the etherchannel.

Use the "show etherchannel port" command.

Among other data, it will show the "Load" of all participating ports in hexadecimal format, like Load: 0x00 or Load 0x0A or similarly.

This will give you a fairly good picture of traffic distribution across the 4 links.

How is you setup is working?

Are you OK with it?

Cheers:

Istvan

I forgot to point out that I never specified the "port-channel load-balance {load-balance method}". My etherchannel is working with just all the settings I sent you before.

So, if the load-balance method is not specified, does the Layer3 4506 switch use a default one?

I guess a really good test will be shutting down one of the 4 interfaces to see if the channel still up. I have to play with these settings in order to be 100% sure that all interfaces in the etherchannel are working

The part that got me was "channel-group 1 mode active". According to the readings, this "active" word turns on LACP. So it wasnt working. I looked at the nortel switch config and no help as I have zero clue about it. But doing a search on nortel config examples, the word LACP was specified, and in my nortel switch was not, so I assumed LACP wasn;t on so I made all those nortel interfaces static trunks, placed them into trunk group 1 and then it worked.

Baby steps but we're getting it done

I just entered the command and it reports Load = 0x00 on all. I will be doing more "sh int giga2/11" comands to see the activity there.

On the nortel side, the status of the trunk comes back as "forwarding" on all 4 ports. So I assume this is good

Hi,

i am trying to configure the same setup beween IBM bladeCenter ( Nortel ) and Cisco 4500 Switch

Can u help me in this configuration Specially from the Nortel side ?

Regards

Mohamed

Hi Mohamed,

I remember this project which turned out to be no fun. I basically got this working by reading all the Nortel and IBM Blade Center manuals... lots of print-outs.

You'd need to understand the architecture of these systems first. I highly recommend this. I am by no means a nortel guy, but once I read thousands of manuals, articles, examples, etc., I was able to configure those nortel switches.

what exactly are you having problems with?