March 1st, 2001, 01:26 AM
Watch, as DocMem crashes a Network
We had an interesting problem a few months back. My boss had an old computer that needed to be upgraded to 64meg of RAM. So he installed it and booted to the network. No problems, but just to be on the safe side he decided to run DocMem on it, and make sure that the RAM was ok. He booted with a floppy, and began the program. I was unaware that he had started this. As I walked back to my office from another mundane problem someone grabbed me and told me about how they could no longer print, I thought: "Well, its going to be one of those days." Not thinking anything of it, I began to troubleshoot the basics. HMMM... Everything seemed to be ok. I better check the IP on the printer. What? It had dropped its IP. Then at the same time there were people coming in from everywhere telling me all about how they couldn’t print, logon, and various other problems.
We started to troubleshoot. Where I work there are 4 machines that need to be logged on all the time so users can access a DB and send data to one of our servers, so needless to say this was happening at a bad time. (but then again, a network crash never does happen at a good time. LOL)
After various Server boots, and looking at some other problems I walked over to the HUB to take a look, and possibly change a few ports. There were collisions everywhere...
4 hours later after walking around the entire building and unplugging every computer that was "different" we still could not figure out what was going on. (seems that we walked by that machine 4 or 5 times, thinking nothing of it... The mem test had finished and was just sitting at the prompt saying that it had passed.) Between the two of us we just ignored it.
Finally after beginning to think that we were going to have to call someone in, my boss went in to pull that computer back down, and bring it in to finish setting it up for someone else. Poof! Everything started to work again... A friend told me that some old NIC's will do some funny things when the MEM is all used constantly, but I had no idea.
Tell me; Future-Boy, who’s president of the United States in 1985?
March 1st, 2001, 04:38 AM
There were quite a few old OLD network cards that used a 4k or 16k block of upper memory as a buffer area. If Docmem searches for upper memory blocks and writes to them, no telling what would happen.I've had situations where trying to free dos-640 area for Dos applications caused the netcard to hang the network (by loading dos drivers in upper memory occupied by the network card).
What's the differance between 'twisted' and 'torqued' anyways?