Disabling eth adapters in AIX

In the current AIX releases (7.x) there is no way to completely disable unused ethernet adapter. This may cause performance degradation when "entstat -d" or "netstat -v" are issued or other tools try to get statistics from this adapter.

After system boot or the cfgmgr command was executed the adapter is "available", but that doesn't mean, that the adapter is in open state.
Really the ethernet adapter is only in open state if the adapter is a part from an EC or SEA adapter or if you have configured a IP address on the related interface.
But if the adapter is not in use, then the adapter is in closed state. If we start in this situation the "entstat -d" or "netstat -v" command, then the system need to change the adapter status to open state,
before the commands can read the adapter status.
This process need one CPU, but you can not forecast, which CPU the system use for the netstat or entstat command.
And other application can work slower or hang if that application is trying to usie the same CPU.

The following mitigation's exist:
1- Unload the device driver for unused adapters
# rmdev -l entX
This avoids the problem, but every reboot or cfgmgr run will load the driver again.

2- Activate a dummy IP address on the unused adapters
This puts the device into "open" state and reading the statistics will go fast without blocking a CPU. It's NOT enough to do a "ifconfig enX up", you'll need to assign an IP address!

3- Use a loop-plug or cable the port with a suitable ethernet cable with a switch port. This may be not applicable at all if there are no free ports.

4- For netstat -v and entstat -d you can use the environment variable ENTSTAT_MODE. the ENTSTAT_MODE varaible solve only the problems with unused ethernet adapter if you use the entstat -d or nestat -v command. The variable is not helpful, if you have monitoring tools that open the adapter socket in the program code without using the entstat or netstat commands.
All of these mitigation methods do not resolve the issue for 100%. We request development of a AIX core tool/procedure that completely disables ethernet adapter that is not configured/plugged to the switch.
To be short: we need to implement in AIX the following method to disable ethernet adapters, similar to how it is done for fscsi adapters:
# chdev -l entX -a autoconfig=defined
# chdev -l entX -a autoconfig=available