topic ELRP to disable a port when Switch is connected in ExtremeSwitching (EXOS/Switch Engine)

ELRP to disable a port when Switch is connected

Nico_Lueck — Tue, 05 Nov 2019 22:08:37 GMT

Hi Community,

having a customer which is using ELRP on access ports and spanning tree on uplinks.

Now he comes with a question if it is possible with ELRP to detect a switch connected to an access port and deactivate that port.

As for my understanding, ELRP can’t do that.

Is there may be a workaround for that?

Thanks regards

Nico

Re: ELRP to disable a port when Switch is connected

Alexandr_P — Tue, 05 Nov 2019 22:31:34 GMT

Hello, Nico!

As far as I know: for ELRP no matter - is it switch, or hub, or other network equipment connected to port.

ELRP is pretty simple - it’s send packet. If packet come from some other port, then ELRP is blocking port, or make warning.

I think you can use NAC (ExtremeControl) to check what type of equipment is connected to port and make some decision.

Thank you!

Re: ELRP to disable a port when Switch is connected

Stephane_Grosj1 — Thu, 07 Nov 2019 17:43:06 GMT

Hi,

there’s no built-in capability with ELRP to react on the device-type connected to a port. As Alexandr pointed out, it doesn’t really matter and you could detect a loop across a switch/hub connected to the port anyway.

If you want to do that, you can always use UPM, and look at LLDP info. But that would require some effort and dev. You have to figure out if this is worth the effort.

NAC and Policy could be an elegant alternative.