Are the 2 3750Gs in a stack configuration, so they are acting like one switch, or are they separate? If they are stacked, you can use the config above.

Unfortunately, if they are 2 separate switches, you will not be able to do port channel between them unless you run more connections from the 6509 to each 3750G (each 3750G will need 2 cables back to the 6509).

You can still create the trunk to pass multiple vlans to the 3750Gs though.

Please let me know if you have any more questions.

Thanks
Joseph.

I can setup the etherchannel connection, and your are right that i no need to manually configure the port speed as default setting for the cisco switches are set to auto negotiation, so as i connect the 3750 to the 6509, i can see the connection are up and the speed settings is set to 100Mbps full duplex (auto negotiation).

Thank you

Have a nice day !

The difference in port speeds should not be an issue. When you connect the 3750 to the 6509, the 6509 should configure its ports to run at 100Mbps full duplex. You can manually configure the 6509 ports to run at 100Mpbs full duplex, but you should not need to do this.

Once the connection has been made and the interfaces are up and communicating, you can setup the Etherchannel connection.

Let me know if you have any more questions.

James

I have one question regarding Cisco EtherChannel, let assume i am having a cisco 3750 switch and a cisco 6509 high end switch. Can i create a pair of etherchannel connections between them?

My concern is because of 3750 switch are running on FastEthernet 100Mb ports, while 6509 switch are running on GigabitEthernet 1000Mb ports. Because i heard it somewhere you need the same speed for the EtherChnnel to be worked.

So can i create the etherchannel? Or i need to configure the cisco 6509 ports speed settings to auto/100-full deplex to make it work?

Thank you,

Have a nice day !