Flapping ports on 4000m and 4140gl switches

[Wojciech Furmankiewicz_1]

Hello,

My customer has a problem with flapping ports.

I 05/09/05 07:53:34 ports: port C6 is now off-line
I 05/09/05 07:53:37 ports: port C6 is now on-line
I 05/09/05 07:55:29 ports: port D3 is now off-line
I 05/09/05 07:55:31 ports: port D3 is now on-line
... and the same for almost all interfaces.

There are two switches connected together: 4000m and 4140gl.
Some vlans are configured.
The firmware is current on both.
All the links are configured for 100FDx on both sides.
LACP was disabled on all interfaces.

Does anybody have and idea what can cause that problem?

Thanks in advance for help !
Wojtek

[Les Ligetfalvy · Accepted solution]

Are these switch to switch connections or end device connections on the edge?

[Wojciech Furmankiewicz_1]

The flapping ports are connected to the end devices - PCs

[Les Ligetfalvy]

Try newer drivers and turn off power management. Worked for me.

[Søren Fisker]

I've been struggling with HP with the same issue on 2650's for more than half a year. We've disabled DHCP, STP, LACP, IGMP and so on which has made absolutely no difference.
It occurs on all ports whether connected to Intel, Realtek and Broadcom NICs, so I'm pretty confident that it's a switch issue.
However, HP believes it to be driver problems or faulty cabling...
With all the different types of NICs and driver versions we have, I'm pretty sure that there would have been a couple of computers that didn't exhibit this problem, but there isn't...

Regards,
Sør

[Wojciech Furmankiewicz_1]

Hi Soren,

Thanx for your reply.
Did you finally found the clue?
What was it?
Or do you still have the problem.
Do you think replacing the switch will solve the problem?

Best Regards,
Wojtek

[Les Ligetfalvy]

I had an issue with a 2848 that was toggling ports and newer code on the switch fixed that. I also have seen toggling on my 5308xl from two separate causes.

One cause was marginal jumpers. The patch cords were over-crimped, resulting in the contacts being too deep between the insulating spacers. This caused the spring pressure on the contacts to be diverted to the spacers instead. I have been replacing them whenever I encounter the toggles.

The second cause I attribute to drivers and power management settings. I had a few PCs toggling and when I updated the drives and turned off power management, they ceased to toggle.

[Stuart Teo]

i experienced flapping between a 4000m and some workstations. i never found out why. i only know that when i nailed both ends at 10hdx, they stopped flapping. :(

[Les Ligetfalvy]

I had one user plug a paper shredder into the same powerbar as his PC and every time he shredded documents, the switch port his PC was connected to would toggle.

[Stuart Teo]

sounds like harmonic distortions!

get a filter! :)

[Søren Fisker]

Wojtek: I'm sorry to say that we didn't get anywhere at all. Nothing, zilch, zero, zip.

Les: When you say power management, do you mean in device manager, select the NIC, and then the power management tab?

So this means, that Realtek, Broadcom and Intel NICs shouldn't be used with HP network equipment?

Or that Windows XP SP2 is incompatible with HP network?

Or that XPSP2's power management is broken?

And that HPs desktops (Evo510, 530, dc7100) and laptops (nx5000, nx7010, nx6110) are incompatible with HP network?

No matter what - it sucks.

S.

[Søren Fisker]

Anyone tried this:

How to disable Media Sensing for TCP/IP in Windows:

http://support.microsoft.com/default.aspx?scid=kb;en-us;239924

?

Soren

[Magnus_18]

Soren:

Have you tried different patch cables? (or maybe even connecting a computer directly to a switch without going through patch panels)

In my experience flapping ports usually occurs because of bad cables.

[Jeanniard]

Hello,

I encounter the same problem on multiple 2650 switchs only for 5 month ago. I've posted some informations on the thread : 85666 for that.
We have a large network with approximately 30x2650, 3x2626, 4 HP5308xl and Cisco 2950/3550/3750 with cat 5e + Cat6 brand new ITT cabling system. Port flapping appears on all 2650 switchs (actually we qualify that toggle doesn't appear on 2626 switchs) sometimes and with no reasons.
We have updated all the switchs to H.08.69 firmware this week, test some things from forum like power management and updating drivers but the problem still appears (we have tried to modify rstp, cdp, flow control, LACP, speed-duplex negociation, mdi-mdix negociation, ports and cables).
HP tells us that no know problem exists about that !
So, I would try to modify Windows registry to ignore media sense.....

So, have you test that flaping appear on the same place by replacing 2650 with another switch like Cisco or 3 com ?

[Wojciech Furmankiewicz_1]

Hi,

Thank you for all the answers. By now the problem is not solved. There is an issue with power network onsite. Existing voltage on grounging pins and some other things. They are working on it at the moment and then will observe whether is better or not. I'll let you know.

My Regards,
Wojtek

[Les Ligetfalvy]

HEHEE
Ja, ground loops can be a big factor as with my paper shredder user.

[SergeyL]

Hello,

Has anybody resolved issue with flapping ports?