[AIX] Etherchannel Configuration and Change

Etherchannel is a aix software utility which makes improving network performance and providing availablility using more than 1 adapters.
If you make the adapter being etherchannel, new adapter is generated which can use as an normal ethernet adapter.

note) If you use the etherchannel to be active-backup mode, you can connect it to different switch devices. But if you want to use Active-Active mode, you should connect same switch.

1. Prepare network adapters for making an etherchannel.



2. Geneate an etherchannel
You can make the etherchannel easily using smit interface.

# smitty etherchannel




- Select [Add An EtherChannel / Link Aggregation]
And select an available network adapter for using active channel.
(One or more items can be selected.)

We will use Active-Backup mode, so select ent0.



- Next, you can see the below screen, etherchannel config menu.


First of all, you should select backup adapter. Move the cursor to 'Backup Adapter', you can see and select available adapter. (Print list : ESC + 4)



There are other option

- Alternate Address : the made adapter uses default MAC-address, but can use other MAC address using this option
- Enable Gigabit Ethernet ... : carefully use this option because it changes MTU to 9000. If you use gigabit network and all other systems supporte MTU 9000, this option makes performance good but if not the performance being poored.

- Mode: for selecting ehterchannel mode.
          Standard : transfer data on each requested adapter
          Round-Robin : transfer data sequentially on each adapter

- IEEE 802.3ad Interval:  Using link aggregation(wide bandwith)
                                  Should use LACP switch.

- Internet Address to Ping : For finding problem about connection, system tried to send periodic ping request. It needs to be used carefully. Because if other system, receiving requests, is having problem, own system will tried to failover to backup adapter.
In this result, the adapters which is etherchanneled will failover each other until the opposite system is in normal.

- Number of Retries, Retry Timeout(Sec) : It can used when IP is in Internet Address to Ping and have a backup adapter

- Now you set the option up and press 'Enter', Etherchannel will be made.

#lsdev -Ccadapter


- You can use the ent2 adapter as an network adapter.
   (Input IP address and just use it)

2. You should etherchannel adapter make down and detach status before changing and removing Etherchannel.

3. The procedure, Removing an active or a backup adapter
- Check whether the removing adapter is used

On the picture etherchannel is consisted of Active(ent1), backup(ent0)



Active channel is primary channel. It means etherchannel is running on ent1.
So you can replace backup channel(ent0). need failover if you want to replace active channel.

- How to failover
# smitty etherchannel

Select 5th item on the list at below picture


Next
#smitty etherchannel   => Change/Show Characteristics....... =>  Select etherchannel

- Input the adapter you want to remove on 'Delete Backup or Main Adatper'
- If the action is completed, backup adapter will be removed as below picture.
- After removing, replace fault adapter.




Replace proceudre of adapter
- rmdev -dl 'Error_Adapter_name'  (Error_Adapter_name: Input fault adapter name)
- Replace it (diag – Task Manager - Hot Plug Task – PCI Hot Plug Manager)
- # cfgmgr -v


4. Add  Active / Backup adapter in the etherchannel
- It's similar to number 3, Remove procedure
  Insert the adapter you want to add to Add Main adapter or Backup adapter.




That's all