Problem with Etherchannel

UNIX AIX
1

I'm trying to configure Etherchannel on AIX 5.3 and I'm having some problems. I am aggregating both of the onboard NIC's (ent0 and ent1) into a new adapter ent2 for failover reasons obviously. At first I was experiencing a problem where about 50% of all my packets would be dropped. Then after removing all the network devices and rediscovering and recreating the aggregate, it is much better but I am still losing about 1-2% of the packets.

I am assured that there is no problems with the switch configuration, and I have verified that both network cables are working properly.

I'm hoping that someone will point out something that I have missed in created the aggregate.

2

Can you supply more information about how the etherchannel is configured? E.g. could you post an
# lsattr -El <your etherchannel ent device>

3 
# lsattr -El ent2
adapter_names   ent0,ent1      EtherChannel Adapters                       True
alt_addr        0x000000000000 Alternate EtherChannel Address              True
auto_recovery   yes            Enable automatic recovery after failover    True
backup_adapter  NONE           Adapter used when whole channel fails       True
hash_mode       default        Determines how outgoing adapter is chosen   True
mode            standard       EtherChannel mode of operation              True
netaddr         0              Address to ping                             True
noloss_failover yes            Enable lossless failover after ping failure True
num_retries     3              Times to retry ping before failing          True
retry_time      1              Wait time (in seconds) between pings        True
use_alt_addr    no             Enable Alternate EtherChannel Address       True
use_jumbo_frame no             Enable Gigabit Ethernet Jumbo Frames        True
4

Well..... Your etherchannel configuration seems OK to me but the server side is only half of the equation. Use
# entstat -d ent2
to find out if there are errors visible on the physical interfaces and the link aggregation status. Use the information from IBM Systems Information Center to get detailed status information. If necessary get back to the switch admin to find out whether your Etherchannel config works with the switch port setup.

5

I found the problem...

I was configuring the controllers to act as a load balancing etherchannel controller. This normally would not be a problem, but I had each NIC connected to a different switch.

I removed the Etherchannel adapter and recreated a new one with a primary/backup failover configuration and it is working fine now.