limit-learning doesn't work on stack with EXOS 15.3.1.4

[Ilya_Semenov]

Hello, everybody!

I have a mixed stack of x440 and x460 g1 switches.

I want to configure limit-learning for a certain port.

I say: configure port 3:9 vlan v12 limit-learning 1 action stop-learning

I connect laptop to this port and get an IP. Then I change to another laptop ang get an IP again!

What am I doing wrong?

show fdb port 3:9 show that MACs are changing (and these are laptops MACs)

show port 3:9 info detail show:

MAC-limit = 1, Action = stop-learning.

But nothing happens! I connect third laptop and it gets IP too.

When I say "configure port 3:9 vlan v12 lock-learning" it blocks the port.

Could you please help me with this issue?

Many thanks in advance,

Ilya

[Ilya_Semenov]

Hello, Ron!

I have experience using mac-locking command and know it works, but I live in 15.3 world.

This is very obvious good idea to upgrade EXOS. But the problem is when I upgrade my composite stacks (x440-x460) to 16.2 (or to any of 15.x - higher than 15.3) they start arbitrary blocking ports during daily peak hours. Two years ago Extreme's engineers from Moscow (! - your employees) were unable to solve the problem and left 15.3 as the only stable firmware. The contract is expired now. I 99% sure that it is MSTP issue, totally useless for the current infrastructure (less than 30 vlans). I am going to change STP version to PVST+ on Saturday. Hope it will help.

Thank you!

[Jarek]

Ilya,

limit-learning - specifies a limit on the number of MAC addresses that can be dynamically
learned on the specified ports.

When you disconnect laptop switch clear fdb for that port.
Then you connect new device, switch learn new mac address.

If you connect to sw-Extreme port another switch and to this switch 3 laptops,
then switch sw-Extreme will learn only one mac address, all other are blackholed.

--
Jarek

[Henrique]

Hi,

Limit-learning is dynamic. That means the port allows only 1 MAC address at a time (based on your configuration of limit-learning = 1). If you disconnect the laptop an plug in a new one, it will also work.

Lock-learning will "convert" the MAC already learned from dynamic to static and set limit-learning to zero so no new MACs will be added to the FDB.

Could you please clarify what are you trying to accomplish?

Thanks,

[Henrique]

Hi,

When using limit-learning = 1 with action blackhole, if the user tries to use a second device to that port, the second MAC will be added as a blackhole entry to FDB.

configure port vlan limit-learning 1 action blackhole

However, if the user unplug the laptop and plug the new laptop he will get access.

On both cases, they will be able to use just 1 device at a time.

[Ilya_Semenov]

I have 9 stacks with about 2000+ ports...