07-30-2007 01:59 AM - edited 03-05-2019 05:34 PM
I have connected 2 switches together using just one interface - 100MB, now I want to create an Etherchannel of 4 interface so that can have 400MB. As these switches are live, if I start to put the extra 3 interfaces into a channel group, will there be a downtime?
Also o the new switches, can use more than 4 interfaces to get an etherchannel?
Thanks
07-30-2007 02:15 AM
Hi there,
I believed you can have up to 8 ports in each channel group. These can be a mix of different media; for example, you can have some SFP GBICs and some gigabit RJ45 interfaces in the same group. Not sure about mixing FastEthernet and GigabitEthernet though.
For a live environment, I'd recommend doing this under whichever change control process you use within your organisation as changes between switches can be risky, even if this does not cause an outage. Better safe than sorry!
Whether or not an outage will result, though, I'm not sure. I'm guessing your single port connection is not part of any EtherChannel group, correct?
I'm not certain, but if it's not, I think that adding it to a group may cause a spanning-tree recalculation. Adding additional ports to the group should not cause additional outages.
Hope this helps!
Kind regards,
Graeme
07-30-2007 02:54 AM
Hi,
I was adding the new ports to channel, but always with console connection to both devices. That is why I wouldn't recomand reconfiguring the port-channel without backup/failover connection. When two switches will not negotiate channel parameteres, You may be cut off.
Following is the configuration that I am using and thus I can recommand it as safe:
interface GigabitEthernet1/1
description switchB_link1
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
logging event spanning-tree status
logging event bundle-status
logging event trunk-status
speed 1000
duplex full
channel-protocol lacp
channel-group 1 mode active
!
interface GigabitEthernet1/2
description switchB_link2
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
logging event spanning-tree status
logging event bundle-status
logging event trunk-status
speed 1000
duplex full
channel-protocol lacp
channel-group 1 mode active
!
interface Port-channel1
description switchB
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
logging event spanning-tree status
logging event bundle-status
logging event trunk-status
no shut
If You have any more questions, please let me know:
Regards:
Michal
07-30-2007 09:00 PM
Hi,
Check switch port capabilities. It shows which ports can form a etterchannel. There are restrictions on some older switches like the 5509.
Thanks
Salil
07-30-2007 11:01 PM
Thanks. How do you check port capability on Cisco IOS. I keep seeing Show port capability but it only works on CatOS. Thanks
07-30-2007 11:11 PM
Hi
sh interfaces "interface" capabilities
HTH
Jon
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