hp 2610 problem with SX-LC Module (J4858C) fibre connections

[wizzy]

Hi

 

I have just installed 2 hp 2610 switches with SX-LC (J4858C) modules in each linked with lc to lc fibre at 10metre length, for some reason the link keeps dropping between the two and the module lights go off, after sometime they come back again, it is a basic install with just a ip and subnet on each switch and all the default settings left intact! any ideas as to what could be causing it to keep establishing and dropping the connection?

 

Thanks!

[IanT]

Without checking are the modules, are they fully compatible with the switch?

 

Latest Firmware on the switch?

 

Any dust or dirt in the ports?

[glennda]

do the modules actually say HP on them? we accidentally got sold some which did not and had exactly the same problem. Spent like 3 days looking at it then realised they didn't actually say HP on them. and HP have locked out a whole load which have slightly different firmware or something

[wizzy]

Hi,

 

we bought them as a package from a supplier with the modules checked with hp and they are definatelly the correct ones, the fibre cable is also brand new and i have checked for any dust etc and all seems fine, the only thing I have not done is upgrade the firmware on the switches, it seems to work after a while but then goes off I have checked the logs on the switches and nothing is mentioned, the modules do have hp wrote on them and were security sealed

 

thanks very much

[IanT]

Instead of using fiber, have your tried plugging it in via the 2x 1Gb Coppers?

[plexer]

Have you got the ports set to full duplex for each side?

 

Ben

[glennda]

Can u test the gbics in another switch to and check if the problem follows the gbics or try known working gbics in a this switch

[wizzy]

I have tried copper and it seems to work fine, i have left the switch on auto for port settings, and dont have another switch or modules to try?

[plexer]

Try changing the port settings to full duplex on both sides, if that does help has the fibre been tested?

 

Ben

[wizzy]

thanks ill give that a go, no it was a 10 metre prejoined cable that we purchased maybe the fibre is faulty?

[IanT]

Have you looked at the other end where the fiber is connecting too?

[wizzy]

yes checked both ends, plugged into the console port and checked the logs on each nothing is shown, checked for dust etc on the fibre, if the switch is powered down it seems to take hours before the fibre functions again, the only thing I have not tried yet is upgrading the firmware! its all brand new kit aswell!

[featured_spectre]

To check the fibre cable, get a laser pointer and flash it down 1 end, if you can see it the other end, its fine ***

 

Otherwise check the switch ports are set to full duplex, and have no limitations enforced by the default setting.

 

*** Note this is not a proper test, but usually a good indicator

[wizzy]

thanks ill try it and see, ill also try upgrading the firmware and setting to full duplex, cheers

[IanT]

one thing todo also is plug the console cable in, reboot the switch and makes sure it boots up cleanly and look too see if any errors appear in the console.

[plexer]

Also make sure that send goes to receive and receive goes to send from one end to the other.

 

Ben

[plexer]

My money is on duplex both ends though

 

Ben

[wizzy]

well its up again today, but have not restarted them yet fingers crossed, going to try a firmware update to the lastest software and hopefully that will improve things!

[nicklec]

Sorry to be a 'troll' but why 2x GBICs over some cat6? Seems rather OTT for 10m!

[IanT]

Just a word of warning, HP firmware process is a bit funny sometimes, it doesn't show you any form of progress bar or anything when its upgrading, so if its just sitting there DONT reboot it, let it do its thing.

 

Have you also tried booting into the secondary firmware?

[wizzy]

got them free in with the kit so might as well use them!

 

have not tried the secondary firmware yet?

 

someone mentioned today the j4858c only supports 62/125 fiber, maybe this is were its going wrong!

[m25man]

The 4858c works on both 50 and 62.5 fibre.

You will get up to 275m out of 62.5/125 and 550m out of 50/125

 

Your problem is more likely to be an unstable module, you have already stated that the link has worked for a period without issue so that eliminates all of the other comments regarding polarity and duplex settings.

 

Watch your patch lead make sure it is a multimode 50 or 62.5 as I have seen many people use a singleMode patch by mistake!

 

Faulty GBICs will be easily aggravated by the short distance your using, only calibrated tools will be able to confirm this.

I use my etherscope with a known module and a loopback fibre to set a reference loss level the test the fibre and the module to verify links and loss levels.

A greasy finger on your patch cord end can easily put 3db loss on the link so make sure they are all clean!

 

Any loss >6db is normally game over, avoid any bend radius in the patch lead smaller than a coffee cup this is where problems begin.

 

I too would also recommend you use copper for these short hauls, at least you could trunk the two gigabit links to give better bandwidth than the free GBICs

 

Why were they free? Probably because they are the same mass produced $25 units with an HP sticker on them, that you can get from a hundred suppliers in Hong Kong...

They have an expected DOA rate of around 3% so if you must use fibre for your short reach inter connect get a spare and replace each unit in sequence and see if you solve the problem by substitution.