loopback-detedction timer

Topic

Hi all,
I’m a new user of the network devices omniswitch alcatel.
I’m trying to configure the loopback-detection on a alcatel 6860N. I’ve configured the trasmission timer at the value of 5 sec.The problem is that (in my test lab) when I create a loop between two ports ,the interfaces goes in a shutdown state after a variabile time between 5 and 120 sec. It’s a correct behavior? 120 sec is a lot of time when a broadcast storm is coming….
Greetings….

Date
14.02.2023
answers
2
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Author
Asked by rob_mag

Answers

Hi,

stp is disabled on the switch and this is why I use loop detection to avoid broadcast storm due a clumsy users...

Date
06.04.2023
Author
Asked by rob_mag
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Hello,

Normal behavior is that the switch periodically sends out LBD frame from loopback detection enabled port as per the transmission timer (which is by default 30 seconds) and concludes that the port is looped back if it receives the frame on any of the loop-back detection enabled ports.

Date
15.02.2023
Author
Asked by adongula
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Hi adongula, you're right when you say "that the port is looped back if it receives the frame on any of the loop-back detection enabled ports.",but my concern is about the intervention time of the loopback-detection. I mean : I plug the ethernet cable in a loop configuration . Why the interface recognissed in looped back goes in shutdown after a variabile time between 5 and 120 sec? If the switch send LBP every 5 sec ( I set the trasmission timer to 5 sec) the loopback mechanism shouldn't turn-off the interfaces after 5 seconds? Why instead the interface goes in shut-down state after a variabile time between 5 to 120 seconds?
Are both ports loopback detection enabled ports? Is STP disabled on both ports? What STP mode are you using?