Solaris 9 UNIX system won't boot

So today I troubleshooted my very first real live UNIX disaster. Luckily this is on the machine I am learning on so no big deal. But I finally got to apply what I learned for the first time in a real life situation.

First off, a couple links that really helped me out.
Link #1: How to change the default boot device
http://docs.sun.com/app/docs/doc/817-1985/6mhm8o5oa?a=view

Link #2: Booting problems in Solaris
http://www.adminschoice.com/docs/booting__problems_in_solaris.htm#%22The%20file%20just%20loaded%20does%20not%20appear%20to%20be%20executable.

I wish I could thank whoever wrote those pages. But for now, here's what happened.

One morning, I came in and the screen displayed this:
"Timeout waiting for ARP/RARP packet"

I am still new to UNIX (been taking classes for only about 6 months so far) so I wasn't sure what that meant. So how to fix it? Well, just like in Windows, power off the machine and power it back up. Right? LOL. Well normally wrong but this time I got lucky. It booted and away I went.

Then this morning, same thing happened. And coincidentally, it all happened at the same time I started learning about file systems and formatting and whatnot. Maybe I mucked something? Well either way, I finally figured out how to fix it.

1> While it repeats that ARP message thing, press [stop]+[a] on the keyboard. This gets you to the OK prompt.
2> Then I type "printenv" from the OK prompt. I see a list of things with settings. There are 3 things that should be set like this:

boot-device disk
mfg-switch? false
diag-switch? false

I first noticed that "boot-device" was set to "disk net". So somewhere along the line that got changed. Was my machine hacked perhaps? Who knows. Also, "diag-switch?" was set to true. So I changed these items to their correct options like so...

OK setenv boot-device disk
OK setenv diag-switch? false

And then typed "reset" to reboot the machine and take the settings.

OK reset

And whaddya know? The machine begins to boot! Hooray. Somehow, someway, I must've fubarred the boot block. So that was part of the problem. Another part of the problem is that I managed to get it connected on the network but I'm not real good with that yet so it's possible that it got hacked. Or maybe I am just paranoid? Either way, after "correcting" all the block parameters, it's not fixed and I'm back in actioon. Hooray!