01-15-2004 02:49 PM - edited 03-02-2019 12:55 PM
I have 6 Catalyst 3750 switches in stacked configuration running IOS version 12.1(19) EA1.
I need to know if EtherChannel can be configured between ports from different switches. It took the configuration, For example, here is the config
interface Port-channel1
switchport trunk encapsulation isl
switchport trunk allowed vlan 2-4,9,254
switchport mode trunk
no ip addres
interface GigabitEthernet1/0/1
switchport trunk encapsulation isl
switchport trunk allowed vlan 2-4,9,254
switchport mode trunk
no ip address
channel-group 1 mode on
interface GigabitEthernet2/0/1
switchport trunk encapsulation isl
switchport trunk allowed vlan 2-4,9,254
switchport mode trunk
no ip address
shutdown
channel-group 1 mode on,
-----------------------------------------------
Now, observe the Spanning Tree outputs on port-channel, gig 1/0/1, and 2/0/1
show spanning-tree interface port-channel 1
Vlan Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------
VLAN0002 Root FWD 3 128.472 P2p
VLAN0003 Root FWD 3 128.472 P2p
VLAN0004 Root FWD 3 128.472 P2p
VLAN0009 Root FWD 3 128.472 P2p
VLAN0254 Root FWD 3 128.472 P2p
show spanning-tree interface gigabitEthernet 1/0/1
Vlan Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------
VLAN0002 Root FWD 3 128.472 P2p
VLAN0003 Root FWD 3 128.472 P2p
VLAN0004 Root FWD 3 128.472 P2p
VLAN0009 Root FWD 3 128.472 P2p
VLAN0254 Root FWD 3 128.472 P2p
show spanning-tree interface gigabitEthernet 2/0/1
no spanning tree info available for GigabitEthernet2/0/1
Why int gig 2/0/1 wouldn't give any info on spanning-tree. Really Wierd.
Any idea?
Thanks,
01-16-2004 06:41 AM
Yes it is possible to configure an etherchannel across the stack. It is known as a cross-stack etherchannel and is described in the "Configuring Etherchannel " section of the 3750 Config Guide.
URL: http://www.cisco.com/univercd/cc/td/doc/product/lan/cat3750/12119ea1/3750scg/swethchl.htm
01-16-2004 06:43 AM
oh, gig2/0/1 is not providing any STP info because it is shutdown. At least that is what is shown in the output you submitted.
01-16-2004 05:26 PM
I sent the configs with the port shutdown. But I unshut it, and still no information on STP.
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