I set up a privately funded classroom lab of 32 Imacs running os 9 in a large high school with a mainly pc network. As the combination of Novell and OS 9 is a headache to configure, I let the nervous techs know that I would run a closed loop to avoid any problems. I set up all my machines to pull a fixed IP from a range of 192.168.1.100- 192.168.1.133 and tested it with the IP issuing OsX server software (OSX Panther) from a machine I that I had already configured services on just so I could test the wiring to see that everything was physically wired correctly. I simply plugged the single input into my main switch directly into my old Mac. The machines were networkable and all detected. I gave my machines a subnet mask of 255.255.252.0 whereas the school's subnet was 255.255.255.0 with a completely different root Ip address number. I then decided to upgrade to better server hardware and left the Imacs turned off. I was then told I could hook my new server to the internet as long as no physical connection was made to my closed loop network. This worked fine and I dropped any more work on configuring my new server (OS X tiger) as I had some other hardware issues i.e. different hard drives and controller cards I was researching. This new server software, therefore, had no services turned on whatsoever and was simply functioning as a stand alone machine with clean updated software install. In any case, sometime later, I was installing some flat screens and decided to clean up the cable clutter under the server desk. The next morning, all He double toothpicks broke loose and they told my wife that I had plugged in a cable wrong and brought down their whole Novel client system, plus Email, etc. etc. They also cruelly told her that nothing was backed up and they had lost every ounce of data for the entire school corporation for the entire year. When I heard this, I stopped believing anything more I heard, as I knew IT people back up as a matter of religion. Here is the core of my responsibility. If I did anything wrong, it was to mistakenly plug my closed loop in-feed into an 8 port switch as I had two grey Ethernet cables right at the same place. So here is the picture. At the worst case, I left my unconfigured server turned on overnight with the lead in to my closed loop plugged into a powered switch that had a live feed from their network (This configuration has worked just fine for weeks sans my big mistake). There was also a Novel configured PC plugged into the same switch, but it was not turned on. None of the rest of the switches in my closed loop were powered as all floor plugs powering the system were pulled. None of the Imacs were powered on. So could this have caused such a major echo effect (I think they called it that) with such a drastic affect so as to drastically slow down if not crash an entire network. If it did, hammer my amateur incompetent posterior so I don't ever make this mistake again, but I have a hard time believing that one misplugged powered switch leading to a completely unpowered network (machines and switches alike) could have a very large system wide backlash. My final clue is that they could not get their system running at normal speed(it never crashed) for several days after they killed the Ethernet feed to her room and it is still to date, from what I understand, running slow.
So, just how big was my screw up?
