switch crashing needs restart

Hi guys

month or so ago, i was told to go round whole school reduce the network card speed from 1gb to 100mb!! dont ask why...stupid decision by the county!!

since then, every now and then the switch some how crashes, the whole network goes awfuly slow. the only way to restore it to good speed it power down switch and power back on. these are brand new switch. only year old.

would the speed slowness have some effect on this or is it something else?

as i have my eyes on the reduction of network card speeds. before that was lowered, we never had this issue

 

npe they not managed switches. i had to go round each machine and change network card settings manualy!! 300 machines!! LOL!! was JOB AND HALF!! but someone from county said to school he a network infrastructure specialist so i had to do as they say even though i said reducing to 100mb will NOT speed up network

 

I don't even see how a 300 computer network would even run without managed switches.

 

its a primary school. i have actualy worked at many primary schools and neither of them have managed switches..managed switches wouldve been better

 

Did you actually change the setting from 1gig to 100Mb/s, or did you actually change from auto to 100Mb/s?

If the later (which I suspect is the more likely), I wonder if the problem is not that you've reduced the speed from 100Mb/s, but that in effect you've forced some connections up to 100Mb/s full duplex.

On auto, the switch and NIC will auto-negotiate the best speed to work at. If you've got sub-optimal connections (too long runs, poor shielding, dodgy port etc.), the system will drop the connection speed until it gets a reliable connection.

As your school network seems to have been purchased on a very tight budget by people who don't recognise the value of managed switches, I'd be very surprised if they didn't also skimp on the cabling. I expect you have a few connections that are dodgy and on auto, actually run at 10Mb/s.

The fixes are probably:

1. Get some sort of network sniffer or decent cable tester, and check every connection. Expensive (decent test hardware is not cheap), and time consuming.
2. Install managed switches that give you error reports and therefore allow you to track down where the problems are
3. Set the NICs back to auto
4. Try and find the dodgy connection by trial and error. On an intermittent fault that will be a nightmare.

Of the four, I think option 2 is the best. However, 3 is the cheapest and simplest.

 

i have told the school to look at purchasing managed switches. I heard they bought the switches second hand last year as well!! lol..i thought they was new...

not sure if it will work, but no harm in trying it out but in mean time i will revert all machines to auto again. And yes it was actually on Auto and i changed it it 100mb