Quick port channel question

[Levili]

This should be easy for you guys that work this stuff every day, but I only touch it once in a while, and want the most simple solution. Do i need to define switchport commands for BOTH the portchannel interface and associated members, or can I just define them on the portchannel and add member ports without the extra commands? Example: int p1 switchport mode access switchport access vlan 10 int range g1/0/9 - 10 channel-group 1 mode active (or do I have to have switchport mode/access stuff here as well) And more generally, if I define the member ports, do I also have to add the same commands to p1? Yeah, I know I can just tinker with it and find out, but under the weather and cant think so well/dont have patience for it.

[paul driver]

Hello
When creating a L2 portchannel, you first assign the physical ports to the portchannel (channel-group mode xxx), the Logical port-channel interface will then be automatically created, then you would define the switchport commands on that port-channel which will populate the physical interfaces.

Example:
conf t
default int range gig0/1 -2
int range gig0/1 -2
shut
channel-group 1 mode on | active
exit

int po1
switchport mode trunk
switchport trunk allowed vlan x x x
exit

int range gig0/1 -2
no shut
exit

[MHM Cisco World]

from Cisco Doc.

""After a Layer 2 port becomes part of a port channel, all switchport configurations must be done on the
port channel; you can no longer apply switchport configurations to individual port-channel members.
You cannot apply Layer 3 configurations to an individual port-channel member either; you must apply
the configuration to the entire port channel.""

[David Ruess]

Hello,

As others have mentioned you leave the interfaces alone (make sure the have all the same settings/default/no configuration). You make the configurations on the port channel and it affects all members. I will note that you should be using a trunk like mechanism for port channels. In your example you give the access vlan command which denotes connection to an end host. Unless the end host is using all ports to send the same traffic, if so I am unfamiliar with what settings are needed. If that's not the case it could cause network issues such as loops or removing ports form the port channel automatically.

-David

[Joseph W. Doherty]

It depends on the platform.

Generally you want to do a much as possible using just the PC interface, but sometimes you do need to configure individual ports.

Also generally, newer devices and/or IOS versions "better" support just using the PC interface.

(On some platforms, like the 6500, when using different types of Ethernet line cards, you might need to apply "special" commands to allow a port-channel.  [As different 6500 line cards often had different QoS architectures, for example.])