slightly dead switch

[mjs_mjs]

on Monday i came in to find people screaming as they couldn't log on. had a look at a photocopier - saw it couldn't authenticate so went to look for servers.... all were on and working normally, so looked at switches. ahh found the problem. our old core switch (3com 4950) had all it's packet light's on, which it has done before. so i unplugged it and all the network/fibre's, waited about 10 seconds and pluged it back in, then the fibers one by one and then the copper network. it didn't lock up, great problem solved i think - goes to photocopier and i can now log in. within 5 mins it had done the same again. I've now plugged all the coppers into other switches and fibers in where i could, and all the network that is connected it running fine. what could have caused this to happen - it had been plugged in for about 6 months with no changes and no issues. The switch in question has done this before but a quick reboot has solved it previously.

[SYNACK]

Power surge, degraded thermal couple paste on the heatsinks in the switch, age, bad power. I have brought back one switch from this kind of randomness with a firmware upgrade and config wipe but if the hardware is slightly damaged this can just kill it outright.

[hotwired007]

is it configured to self heal? ie detect loopback and dead cables? it could simply be a failed cable thats causing it to lock up - i ahve a few ports on the older parts of the network that cause issues if they are used... (i've blanked them all off so far...)

[mjs_mjs]

Power surge, degraded thermal couple paste on the heatsinks in the switch, age, bad power. I have brought back one switch from this kind of randomness with a firmware upgrade and config wipe but if the hardware is slightly damaged this can just kill it outright.

 

I don't really want to go into this - yes it would be an idea to get it serviced but not by me - last time we had this problem a simple off on solved it. it sits behind a ups so i would doubt a surge, thermal couple, could be but it's in a controled enviroment kept at 16deg, age yeah 6 years of abuse, bad power - other switches are fine so i dunno. thanks tho - i may look at the firmware upgrade.

 

is it configured to self heal? ie detect loopback and dead cables? it could simply be a failed cable thats causing it to lock up - i ahve a few ports on the older parts of the network that cause issues if they are used... (i've blanked them all off so far...)

 

no idea - they were set up by someone else (external). i know tree spanning is on so in theroy no loops can be made, it disables the ports. if it were a failed cable wouldn't i also be seeing odd/bad behaviour on the other switches i've now plugged them into?

 

thanks both for your input so far.

[CyberNerd]

I doubt you can get it repaired - the lifetime warranty is something like 3 yrs after end of sale date - and this switch is really quite old.

I think you need to bite the bullet and get a couple of resilient 5500G's - along with a rolling program for equipment replacement.

[mjs_mjs]

along with a rolling program for equipment replacement.

 

yeah we really do need that. most of our switches holding the network together are 6+ years old.

[hotwired007]

if it were a failed cable wouldn't i also be seeing odd/bad behaviour on the other switches i've now plugged them into?

 

It depends if you've plugged it in i guess and if the other switches are the same... does it lock up when there is nothing else plugged into it? have you tried powering it up with nothing connected to it? does it lock up?

 

Switches should last 5 years easy... i have a few cisco switches that are now hitting 7 years old... they're running fine... just slowwwwww as the rest of my network is 10/100/1000... when i started they were my core switches... :S

[mjs_mjs]

It depends if you've plugged it in i guess and if the other switches are the same... does it lock up when there is nothing else plugged into it? have you tried powering it up with nothing connected to it? does it lock up?

 

Switches should last 5 years easy... i have a few cisco switches that are now hitting 7 years old... they're running fine... just slowwwwww as the rest of my network is 10/100/1000... when i started they were my core switches... :S

 

i did power it up and it worked fine for 5 mins, but it did have things plugged in.

 

to me this wasn't a good switch at the time - was wrong for the type of network/size, and now i should see it in another rack doing edge or distribution services not being our core switch. now we have a littel cisco switch doing it - 24 Gb ports no fiber. but funding doesn't allow the network to be looked after.

Edited July 28, 2010 by mjs_mjs

[mjs_mjs]

rite - i'm gunna just plug it in on the network - doing no work but just to get it back 'online'. will see what happens....