Lost the network???
Page 1 of 2 1 2 LastLast
Results 1 to 15 of 29

Thread: Lost the network???

  1. #1
    Registered User Deity's Avatar
    Join Date
    Mar 2001
    Location
    Elsewhere
    Posts
    1,412

    Question Lost the network???

    Here's an interesting one...

    My company recently upgraded some network components. We removed a 24-port 10MB Netgear Hub and replaced it with two 16-port 10/100 Linksys Switches. After connecting the systems to the switches, about 95% worked perfectly. The other 5% lost sight of the network. Here's what I know...

    The network is a TCP/IP network running all Win9x systems.
    The systems that are affected use a CNET Pro120(b) 10/100 NIC. (This same card & driver version are used in other systems that do work) I have connection lights on both the switch and the NIC to the systems that are not working. I cannot browse or ping any system on the network. The systems can ping themselves.

    Here's the real confusing part...
    If the speed setting is manually set to 10MB Full-duplex, the system works perfectly. It will browse the network and perform all normal functions. If the speed is set to automatic or any other manual setting (100MB half-duplex, etc.) then the system stops seeing the network again.

    Any ideas?

    Thanks in advance.
    A bored admin is a very dangerous person...

  2. #2
    Registered User MacGyver's Avatar
    Join Date
    Oct 2000
    Location
    Ottawa
    Posts
    4,232

    Post

    Wild Idea: The cabling between the server and workstations may be poor. Try moving one of the malfunctioning workstations into the server room and connect it directly to the switch with a shorter cable. See if it works there.

  3. #3
    Registered User Deity's Avatar
    Join Date
    Mar 2001
    Location
    Elsewhere
    Posts
    1,412

    Post

    I can connect the cable, back into the old hub and have it work perfectly, so would this be the case?

    I'll try your suggestion though.
    A bored admin is a very dangerous person...

  4. #4
    Registered User MacGyver's Avatar
    Join Date
    Oct 2000
    Location
    Ottawa
    Posts
    4,232

    Post

    With the old hub, were you able to run all the workstations at 100 automatically? I'm thinking the switch is more sensitive to bad wiring for some reason. Call me crazy if you will, but I like to discount the obvious before we decide to "reinstall Windows."

  5. #5
    pretzelboy
    Guest

    Post

    For what it's worth...

    I had a simmilar problem with a 3Com 10/100 Hub. If everthing was configured to use 10mb, then everything worked great. If everything was configured to use 100mb or auto, some machines wouldn't work properly. The cause? The circuitryinside the hub was having issues with automatically switching between 10 and 100. I ended up just having to reset the hub (I believe it was power off and then back on again while holding a button) and presto! Everything worked at 100mb.

  6. #6
    Registered User Deity's Avatar
    Join Date
    Mar 2001
    Location
    Elsewhere
    Posts
    1,412

    Post

    Mac,
    I tried the shorter connection in the server room, but with the same results.

    pretzelboy,
    I'll try resetting the switch tonight, after the users are off
    A bored admin is a very dangerous person...

  7. #7
    Registered User Deity's Avatar
    Join Date
    Mar 2001
    Location
    Elsewhere
    Posts
    1,412

    Post

    These switches have no method of resetting, and I just found out that somebody else, cycled the power last night trying to fix the problem. However, the problem still exists.
    A bored admin is a very dangerous person...

  8. #8
    Registered User Deity's Avatar
    Join Date
    Mar 2001
    Location
    Elsewhere
    Posts
    1,412

    Post

    Well, it turned out to be the NIC itself. I replaced the card with an identical one and it worked perfectly. Not sure exactly how, but why question it. At least until it stops working again.

    Thanks everybody for your help.
    A bored admin is a very dangerous person...

  9. #9
    Registered User Deity's Avatar
    Join Date
    Mar 2001
    Location
    Elsewhere
    Posts
    1,412

    Post

    Correction. The system is NOT working again.

    The new NIC worked for about 10 minutes, then for no reason, it suddenly lost its connection. It would no longer show or ping anything on the network.

    Any other ideas?
    A bored admin is a very dangerous person...

  10. #10
    Registered User
    Join Date
    Nov 2000
    Location
    Fountain Valley, CA
    Posts
    507

    Post

    I had a similar situation upgrading from a 10mb hub to a 10/100 switch. I was disappointed with myself at not finding the solution sooner than I did....

    The problem ended up being that the cabling was not up to CAT5 spec. It was like Cat 3 or something. So while it sufficed for 10mb connection, it crapped out on the new 100mb network.

    So I'd re-check your cabling. Just because it works fine on the hub (at 10mb) doesn't mean it will work on your 100mb switch.

    tk

  11. #11
    Registered User Higg's Avatar
    Join Date
    Jul 1999
    Posts
    295

    Lightbulb

    Have you the posibillity to set the not-working-NICs to 10Mbps fixed (instead of auto)? ... and do they work afterwards together with the switch?
    If not... connect them (only the wrong ones) to your old HUB and do an UPLINK to the new switch... does it work now?

    If you then don't want to recable, perhaps that's a modest solution...

  12. #12
    Registered User Deity's Avatar
    Join Date
    Mar 2001
    Location
    Elsewhere
    Posts
    1,412

    Post

    Cabling is all CAT5 that I personally ran in a new building that we just moved into.

    I did try setting the cards to straight 10MB and they sometimes work when connected to the switch. If they are set to 10MB full-duplex then they work, if they are set to 10MB half-duplex then they don't. *shrug*
    A bored admin is a very dangerous person...

  13. #13
    Registered User BurnFEST's Avatar
    Join Date
    Feb 2001
    Location
    Adelaide, South Australia
    Posts
    603

    Post

    Hmmm so i gather from what your saying that they work indefinetly when set manualkly to 10mb fullduplex? How many systems we talking about here, if its only one or two, is leaving them that way a big deal. Also have you tried changing the net cards for a different type??

  14. #14
    Registered User Deity's Avatar
    Join Date
    Mar 2001
    Location
    Elsewhere
    Posts
    1,412

    Post

    There are only one or two systems affected, but one of them happens to be the boss' computer, so leaving them at 10Mb is NOT an option.
    A bored admin is a very dangerous person...

  15. #15
    Registered User Deity's Avatar
    Join Date
    Mar 2001
    Location
    Elsewhere
    Posts
    1,412

    Post

    Another system went down today. Just as I walked in the door, our legal person said her system stopped responding. Same situation. Different brand network card too. Her system ran fine for about 48 hours, only to drop suddenly from the system.

    A bored admin is a very dangerous person...

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •