Students and Network Cables

[ninjabeaver]

Here's a sort of tip for anyone who's Network suddenly goes really slow then dies.

 

This is the second time this has happened to our network here, and it's such a simple mistake the students can do.

 

Anyways, today at about 09:30 the school network decided to take a nose dive in performance. I hate it when this happens. Panic starts and alarm bells ring.

 

I ran some packet watching software that monitors all network movement and it was through the roof. Luckily, as I've said, I'd seen this before.

 

Bascially, one of the students noticed a network cable unplugged and being the helpful sort decided to plug it back into an RJ45 wall socket. Very sweet. The only problem being that the other end was also plugged into the RJ45 wall socket next to it.

 

This then sent the network crazy and a million phone calls came in telling me the network was not working, or did I know it was not working etc. Then my radio goes off telling me the same.

 

I then had to keep running the packet watching software and unplug one fibre link at a time to wittle down the rooms until I found where the problem was. Took about 20 mins to re-set the system which I thought was quite good for me as the first time was nearly two days. :oops:

 

So if you have the same remember the above.

[ChrisH]

Wow that seems a lot of disruption for something like that 8O

[ninjabeaver]

Yeah, that's what I thought as well. It brought the whole school network to its knees. I'm just hoping the students don't start doing it for a laugh.

 

I'm wondering if anyone knows of a way to stop this?

[russdev]

yes heard of this not seen it here but as soon as kids find out they do it for alughs so just keep an eye on it just do the proccess work from outside of network comeing in a switch until you find it

 

Russ

[Geoff]

Most managed switches have a feature called Spanning Tree Protocol. Enable it and it wont matter if kids (or you!) make network loops.

[ninjabeaver]

yes heard of this not seen it here but as soon as kids find out they do it for alughs so just keep an eye on it just do the proccess work from outside of network comeing in a switch until you find it

 

Russ

 

Thanks Russ, thats what I'm doing. First time round I had to pull network switches all down and then fire them up one at a time until we found the room. This time was alot easier thanks to the new fibre backbone.

 

I was just worried that my network was configured incorrectly and this was a stupid problem of my own making.

 

Thanks.

[ninjabeaver]

Most managed switches have a feature called Spanning Tree Protocol. Enable it and it wont matter if kids (or you!) make network loops.

 

Ah ha, I thought there must be something to help combat this. Thanks Geoff.

[tarquel]

I ran some packet watching software that monitors all network movement and it was through the roof. Luckily, as I've said, I'd seen this before.

 

lol didnt even notice this thread *ahem* before I created my topic in this board regarding this sort of monitoring type tool.

 

Please post there with ome info on what you use if ya cud for me

 

Cheers

Nath

[Geoff]

Ethereal comes to mind.

 

http://www.ethereal.com/

[ninjabeaver]

Ethereal comes to mind.

 

http://www.ethereal.com/

 

That's the one. Using Ethereal I just watched the count jump in 10's of thousands over a matter of seconds.

[MkII]

Our tech department - run by the head of technology and nothing to do with me [until december that is]. Funny - he complained like it was my fault

 

Visiting his area I noticed one port lit up two port lights when I unplugged it. He took me to the wall socket and there was a cable looped into two sockets! Funny you should mention it here - two days later!

[tarquel]

lol I can't remember that ever happening - mainly as theres no spare lead or ports for them to mess about with and there isn't any they can unplug both ends of

 

Interesting stuff tho

 

N.

[KeithFermor]

He He! Yes... this has happened here as well. The cable though was hidden behind a filing cabinet and it was only because of some pretty tight documentation on switch ports vs room ports that had just been completed... that it was found.

 

Our school is a Jarvis school and uses large numbers of EtherWan switches. No documentation, no management and no control! I spotted it by a lengthy process of switch/port elimination.

[Ric_]

Apparantly it happened here not long before I started - it drove my predecessor crazy for days.

 

I don't patch in unused ports - reduced the chance of this and people randomly plugging rogue equipment in

[ConTheITGuy]

Happened to me before - just as the Slammer virus was going round!

 

Nowadays there aren't many spare ports on switches - so if a port isn't connected to a computer (or similar) it probably isn't connected to the switch either!

 

Andy.

[tarquel]

I don't patch in unused ports - reduced the chance of this and people randomly plugging rogue equipment in

 

Indeed - I dont generally, tho people/pupil around here dont generally touch the blank/open ports on the walls.

 

The county used to (when they fitted networking equipment for us) put a patch lead for every port but when they sub-contracted the work to a (crap) company called Daton, they didnt patch up all the ports each time.

 

Its nice to have the cables tho - beats making them lol I tend to leave them in the cabs ready for a port to be patched if needed but generally unplugged for ones not in use (for the exact reason you state Ric )

 

Cheers,

N.

[MkII]

I have 600 ports and some 250+ bits plugged into them - it'd be a nightmare to keep the unused ones unpatched.

 

Our kids stuff pencils in the unplugged sockets as well as paper and chewing gum.

[Geoff]

Paper clips are more fun. You can make interesting smells in the switch cabinet if you do it right.

[MkII]

eek!

[Mango_RW]

Just found this thread, sounds like a problem we had the other day that mysterisouly vanished!

[StewartKnight]

Paper clips are more fun. You can make interesting smells in the switch cabinet if you do it right.

 

That doesn't sound good (gulps) is there anyway to prevent that (apart from asking teachers to supervise kids)???

[Ric_]

Don't patch in the unused ports - that way it is more noticeable if something a port is being abused.

 

You can also buy sockets that are covered over but these are expensive - I'm thinking of fashioning a device to stop the brats unplugging cables. Oh the fun that they have.

[Geoff]

Paper clips are more fun. You can make interesting smells in the switch cabinet if you do it right.

 

That doesn't sound good (gulps) is there anyway to prevent that (apart from asking teachers to supervise kids)???

 

Don't buy Power over Ethernet enabled switches.

[ssimstar]

Happened to me. Think it was malicious, loop plugged into Library switch, which is only there because they slammed desklegs into the data points and trashed them. Took me a few hours to sort, but I did. Nobody cared.

 

 

Here's a sort of tip for anyone who's Network suddenly goes really slow then dies.

 

This is the second time this has happened to our network here, and it's such a simple mistake the students can do.

 

Anyways, today at about 09:30 the school network decided to take a nose dive in performance. I hate it when this happens. Panic starts and alarm bells ring.

 

I ran some packet watching software that monitors all network movement and it was through the roof. Luckily, as I've said, I'd seen this before.

 

Bascially, one of the students noticed a network cable unplugged and being the helpful sort decided to plug it back into an RJ45 wall socket. Very sweet. The only problem being that the other end was also plugged into the RJ45 wall socket next to it.

 

This then sent the network crazy and a million phone calls came in telling me the network was not working, or did I know it was not working etc. Then my radio goes off telling me the same.

 

I then had to keep running the packet watching software and unplug one fibre link at a time to wittle down the rooms until I found where the problem was. Took about 20 mins to re-set the system which I thought was quite good for me as the first time was nearly two days. :oops:

 

So if you have the same remember the above.

[ninjabeaver]

I've started to come down hard on people messing around with the PC's , system and network in anyway, shape or form. They get a public telling off and then the 'you signed the AUP' speech. They then get warned that if it happens again it's detention, and then a suspension for another breach after that.