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Does this sound like something a competent IT guy would say?

Discussion in 'Tech Talk' started by gwalchmai, Aug 8, 2008.

  1. gwalchmai

    gwalchmai Lucky Member

    Jan 9, 2002
    Outside the perimeter
    I'm working with a contractor, who was hired by one of our employees. He's having trouble meeting his deadlines and offered the following in explanation:

    "A technician completely screwed up all of our IP addresses when he was trying to put a color printer demo onto our network. What he did was assign the printer a static IP address, well what he failed to check was that our phone system and network all run static IP’s, so when he put it on line, he caused conflicts that rippled through the network that one by one began to cause conflicts and began taking everything off line. He started before anybody was in the office. I would compare it to a slow poisoning of the network."

    Now, I guess someone might run a LAN with all static IPs if they were masochists, but assigning a conflicting IP to a printer, while stupid, shouldn't hurt THAT much, could it? Maybe they conflicted with the domain controller which was running DNS...

    But isn't preventing such problems part of a competent IT pro's job?

    I think if I'd let something like that happen I would have made up a story about A-Rab terrorists or something. :supergrin:
  2. Ranger375


    May 15, 2008
    Hmm....well...what he should have had happen was this...

    On most Microsoft Windows computers, if you attempt to set a fixed (static) IP address that is already active on the local network, you will receive the following pop-up error message:
    • The static IP address that was just configured is already in use on the network. Please reconfigure a different IP address.
    On newer Microsoft Windows computers having dynamic IP conflicts, you should receive a balloon error message in the Taskbar as soon as the operating system detects the issue: ​
    • There is an IP address conflict with another system on the network.
    Sometimes, especially on older Windows computers, a message similar to the following may instead appear in a pop-up window: ​
    • The system has detected a conflict for IP address...
    On Mac or Linux computers, a similar message will normally appear on screen.

    In other words I would like to know how he forced it to assign two IP addresses that were the same...the other thing is how he would have setup a Standard TCP/IP port connection for the printer after he did this.

    The tech should have known there was a problem. Sounds like more was done than just a conflicting IP address.

  3. geekboy

    geekboy Glock Lover

    Mar 24, 2006
    Tampa Bay, Florida
    Yes, silly indeed. On a really well managed network, even Static IPs are hard-coded into a DHCP server (by hardware ethernet address). I would STILL use DHCP on a network with static IPs using DHCP to assign the statics. Then you'd have a "free" pool for things that don't require static IPs.

    My home network has about 40 devices (includes 5 ReplayTV units, 12 servers, several laptops, 4 desktops, a wireless AP, AppleTV, Cisco Router, etc). Everything is DHCP with static IPs, except for the laptops. And even then, every "rnage" has a purpose...

    (last octet)
    1-20 are routing and DNS equipment (Cisco, Sun)
    21-99 are servers (Sun, Windows)
    100-199 are static IP addresses (including Print Servers)
    201-254 are the free dynamic addresses

    Network planning is important! If your network guy was Network certified, it wouldn't have happened. ;) He would have determined -- or at least asked -- about what your network plan was (like mine above). He would have got a "dynamic" IP address with a laptop, first, and "pinged" the addresses he wanted to use as static addresses. :)

    Even that is not full-proof... but it would have been better than just assigning some addresses in the blind.

    I don't understand the "slow poisoning" of the network. The only way to do that... is to assign the ROUTER'S IP address! yes, I've seen this happen. You're network will run REALLY REALLY slow! Packets missing here and there. Fun to diagnose! That's why I have a network plan. No "computer" -- or end-use device -- gets an IP address below .20... for that reason. Also, some smart folks are making their default gateway not ".1" anymore... making it ".2" or something. Because almost everyone asssumes ".1" is the router.
  4. Patrick Graham

    Patrick Graham Footlong Jr.

    Sep 7, 2001
    Kokomo Indiana
    I'm thinking that if the took the demo printer down the problem would be solved.

    There is probably more to it than that.
  5. srhoades


    Jul 14, 2000
    Usually it would just affect the two devices with the same static IP. However, he may be leaving info out and may have cause a broadcast storm.
  6. SevenFifty


    Jun 3, 2008
    At my house...
    Get a new IT guy...this one obviously doesn't know what he is doing...
  7. gwalchmai

    gwalchmai Lucky Member

    Jan 9, 2002
    Outside the perimeter
    Oh, he's not mine. He was just 'splainin' why he couldn't meet his deadline. No, he's not my IT guy by a long shot. ;)
  8. SevenFifty


    Jun 3, 2008
    At my house...
    Do him a favor and buy him a copy of this book:
  9. Or maybe he shared the same ip_address as a gateway ;) That would cause exactly what was stated above or even ip_address with the DHCP server.

    just my 2cts