Fast Etherchannel 3524-->6509 HELP!

kai.nicholls · ‎11-28-2003

Trying to connect a 3524 and a 6509 across a fast etherchannel. The 3524 and 6509 are in separate buildings and using a laser link at 100Mb.

At present one laser in being used and trunked to carry multiple VLANs both IP and VOIP.

Last night we tried to etherchannel the laser links to add resiliance but failed.

Using a ping test we would lose total connectivity to the opposite building when disconnecting the default connection. When pulling the other connectivity remains. But surely both connections when one is out the other would resume connectivity.

Heres the configuration i used...

3524

===========

int fa0/23

port group 1

speed 100

duplex full

switchport mode trunk

switchport trunk encapsulation dot1q

switchport native vlan #

switchport voice vlan #

switchport priority extend cos 0

no spanning-tree portfast

int fa0/24

port group 1

speed 100

duplex full

switchport mode trunk

switchport trunk encapsulation dot1q

switchport native vlan #

switchport voice vlan #

switchport priority extend cos 0

no spanning-tree portfast

Native vlan and voice vlan is consistant throughout!

6509

=========

set port channel 7/1-2

set trunk 7/1 on dot1q 1-1005,1024-4094

set trunk 7/2 on dot1q 1-1005,1024-4094

set port channel 7/1-2 mode on

Both trunks come up and the channel is shown to be ON

I have read PDF's and searched a little but can't find anything wrong with my setup, it worked in a test environment using a 3524 and 4006!!!

Please help im running out of ideas!!!

Regards..

Kai

aslam · ‎11-28-2003

Kai,

Covering the Basics First:

1. Check if all bundled ports are in the same trunking mode.

2. All of them have the same native VLAN. (did u configure the native vlan on 6509)

3. All of them pass the same set of VLANs.

4. Each of the ports have the same speed.

5. Each of the ports have the same duplex settings before they are bundled. ( check speed and duplex on 6500, dont keep it in auto, hard code it)

6. Bundled ports must also be configured with identical Spanning Tree settings.

On the 3524 type the command

Switch(config-if)# channel-group number mode on

since EtherChannel on mode does not send or receive PAgP or LACP packets. Therefore, both ends

should be set to the on mode.

On the 6500, give the command

Switch-A> show port capabilities mod/port

for the ports you are trying to use and see if they support etherchannels or not.

Use the command show port channel (6500) and show etherchannel summary (3524) and see what they say.

Are you getting any error messages on the console.

Let me know how it goes.

Aslam.

kai.nicholls · ‎11-28-2003

Thanks for the prompt reply. :o)

I can confirm your questions 1-6 are already ok.

The 3524 is IOS not CLI but the command

"channel-group # mode on" is present on the 6509.

I can confirm both switches are capable of Etherchannel and that the IOS is ample.

Log of 6509

===========

2003 Nov 28 09:06:21 GMT +00:00 %DVLAN-2-MACNOTRECONFIRMED:Mac [00-06-5b-5d-0e-c

6] is not reconfirmed

that is the only error that is appearing hourly.

Log of 3524

===========

no errors relating to port group 1 or interfaces 23 or 24.

I will try again sometime soon when i can arrange the downtime changing the channel mode to auto or desirable so it uses PAGP what do you think ?

Regards...

Kai..

aslam · ‎11-28-2003

Sure, that is certainly worth trying, I am not sure what the error message is though, and

Switch(config-if)# channel-group number mode on

is a IOS command as you can see from the (config-if) mode. Can you see if this is there on the switch ?

and once you try doing this also try etherchannel doing load balangin using the IP Address instead of MAC. (just to eliminate that MAC address error we are getting)

let me know how it goes.

Aslam.