[c-nsp] 10gig Link Bouncing Consistently (solved?)

[Justin Krejci]

So the problem is gone. Precise issue not quite identified however. Replaced all of the transceivers and fiber for both links with all single mode + LR optics. It has been fine now since Friday. Hopefully no reoccurrences.

I'm still learning towards something on the netgear side but nothing empirical to back that feeling up at present. So unless some new chapter is added I think this story is about concluded. Thanks for everyone's time and suggestions.

I definitely plan to try and avoid mmf in general going forwards in any case.



-----Original Message-----
From: Nick Hilliard [nick at foobar.org]
Received: Thursday, 04 Apr 2013, 8:41am
To: cisco-nsp at puck.nether.net [cisco-nsp at puck.nether.net]
Subject: Re: [c-nsp] 10gig Link Bouncing Consistently

On 04/04/2013 00:03, Justin Krejci wrote:
> Unfortunately SR/MMF transceivers have no DOM support.

I'd better RMA my SR optics then.  They report DDM just fine, so there's
obviously something wrong with them :-)

> 3. Cable length is between 150 and 200 ft. OM2 should be good up to 150
> meters @10 gig-e. The fiber is also pretty new, perhaps 2 years old.

82m according to http://goo.gl/gf3nG, or 66m if you're using standard
50/125 MMF. The important figure is not the length but the link
attenuation, and the attenuation will be affected if you use patch cables.

Have you cleaned everything thoroughly with one-click cleaners and a swipe
cleaner?  You should get a light meter and measure the rx level at both
ends.  This will tell you whether you are within your optical budget.

Nick

> We'll definitely get some fiber power meter tests ran during "the problem" time @ 850nm
>
> Physical inspection has been completed already as well. No obvious places where there would be any sort of environmental impact and no current signs of distress/damage to the fibers.
>
> Fiber ends have been cleaned thoroughly.
>
> ________________________________________
> From: cisco-nsp-bounces at puck.nether.net [cisco-nsp-bounces at puck.nether.net] on behalf of Michele Bergonzoni [bergonz at labs.it]
> Sent: Wednesday, April 03, 2013 2:29 AM
> To: cisco-nsp at puck.nether.net
> Subject: Re: [c-nsp] 10gig Link Bouncing Consistently
>
>> Beginning several days ago both links began flapping every 5 and a half
>> hours, both links have this happen within a couple of minutes of each
>> other.
>> They will flap for several minutes and then return to normal operation
>> requiring no user action and the ports never enter err-disable or show
>> any other symptoms.
>
> Your story popped me up a distant memory of a heating system that
> happened to leak steam on a fiber cable. That cable contained all the 4
> fibers of a presumed redundant connection.
>
> I would not let the next predicted flapping time pass without:
>
> * "show interface transc det" when everything works, and when things go bad
> * technicians at both ends ready to disconnect one line and test the
> loss on the fibers with appropriate instruments, in the first window
> (~850 nm)
> * physical inspection of the fiber run, if feasible
>
> If the fibers turn out to be OK, when you have a Cisco 6509 on one end
> and a Netgear on the other, and you need to try to replace one of them,
> we all know where to start.
>
> Regards,
>                                 Bergonz
>
>
> --
> Ing. Michele Bergonzoni - Laboratori Guglielmo Marconi S.p.a.
> Phone:+39-051-6781926 e-mail: bergonz at labs.it
> alt.advanced.networks.design.configure.operate
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