hub to switch upgrade problem

Posted on 2011-10-11
Last Modified: 2012-07-11
I would like to update a location that is using an old 10MHz hub, but I am very perplexed.
When I replace the hub with a switch I encounter some connectivity problems. Some computers have faster connections as I would expect, but some computers can't connect at all.
Tried a Gigabit switch then a 10/100 switch, different brands, one new and one used. The used switch I took from a working environment where I knew all of its ports were in use and working.
The network cabling at this location is very old and is in a rough use environment. Some of it is Cat 3.
If I put the hub back into place then all computers connect ok.
Dell server running 2003, 8 client computers running Win 7 or XP, cable modem, Cisco RV220W router.
What could be going on here?
Question by:Bill Simpson
    LVL 16

    Accepted Solution

    It could be the autonegotiation on the links failing. On the ports that aren't working, try setting the links to 10Mb Full Duplex. If that doesn't work, try 10Mb half duplex.

    I would suspect the cat3 cables causing the problem.
    LVL 1

    Assisted Solution

    Cat 3 or station wire, is an unshielded twisted pair (UTP) cable designed to reliably carry data up to 10 Mbit/s.

    Have you tried different cables to the workstations that wouldn't connect?

    Hook up your new switch.
    Plug a computer that connects 100/Mb to the switch port that a non-connecting computer is plugged to.
    If computer still connects, then it may be a cabling or NIC issue for the computer that won't connect.

    Pretty sure replacing cabling, possibly NIC's, should resolve your situation though.
    LVL 11

    Expert Comment

    Cat 3 will definitely be problematic for GBE, or even for Fast Ethernet/100.  To test if the cabling is the issue, try connecting your switch directly to problem computers with a known good CAT5/5e cable.  If your computer can detect and connect correctly with the port, you know the cabling is the issue.  

    If the cable isn't the issue, check if your switches are auto-sensing.  Also check if your computers have old Ethernet cards.  Some old devices just can't work with faster switches (esp. printers).
    LVL 35

    Expert Comment

    by:Ernie Beek
    Agreed, first get cat5/5e and I think most of your problems will disappear.

    Author Closing Comment

    by:Bill Simpson
    I had assumed that a switch would auto-sense down to whatever slower speed might be needed to make the connection. It appears that the existing lines required a slower speed then was possible for connection. Thanks for the help.

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