Member Avatar for dave12345

Hello, Its been a long time since I was studying any of my network stuff, and am rather pressed for time at the moment... I was wondering if anyone might have any hints on how to get this cofig working?
My broadband comes into my router, works great for three comps attached, the problem lies with one of the cables going to an old hub, which connects to one comp. It seems as though the hub won't transfer any info... like a DHCP request :evil:
Think its router problem or hub? one of the two isn't working right to get a connection goin, all the cables work. Thanks for your input!

--dave

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Dani AI

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Short summary: after the checks described by and , the behavior — “cutting off” and then working again after a bump — strongly points to a flaky physical/device fault rather than a router DHCP configuration problem.

Practical next checks that add value beyond basic cable/port tests:

  • Watch the link/activity LEDs on the router, the hub and the client while you plug/unplug. No LED usually means a physical link problem.
  • Swap the hub power brick or try the hub on another outlet; failing PSUs and aging capacitors produce intermittent faults.
  • Try a known-good small unmanaged switch in place of the hub. Modern switches are inexpensive and will eliminate many hub-specific failure modes and performance issues (hubs are simple repeaters; a switch is better). See network hub and network switch.
  • If you want diagnostic evidence, check the router’s DHCP/ARP tables or run arp -a on a client while reproducing the fault to see whether the DHCP/ARP traffic ever reaches the router.

Most likely causes: a loose/broken RJ45 contact, intermittent solder/jack fault inside the hub, oxidized pins, or a failing power supply — these all explain why a mechanical bump could temporarily restore connectivity. If the hub is old, replacement with a small switch is the most reliable fix.

Quick checklist: confirm LEDs, swap power, reseat connectors, test with a spare switch, capture router DHCP/ARP evidence, replace the hub if intermittent faults persist. Avoid opening the hub unless comfortable with electronics — power components can be hazardous.

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Member Avatar for jjorgensen626

So . . .

ISP----> Modem-----> Router----->3pc's?
Router------>hub------>1pc?

I hope this is what you mean.

If so check the cable first, from the router to the hub. Make sure it is good. You can swap cablet to ensure the problem is not there.

Then check to make sure you are using the correct cable (some hubs want a "crossover" cable other hubs use "patch cable" or "straight-through" cable. Some router use an auto-sensing feature, so you can use either type of cable.

Is the client (pc) set to obtain IP automatically?

Can you statically set the IP? example:
IP
subnet
default gateway

you can use the default gateway address for DNS

Lets start with these.

Also . . . has it ever worked?

J-

Member Avatar for dave12345

Thanks for the tips, this was one of my wierdest computing problems yet, because the hub was essentially cutting off the signal, i tried pinging from both ends, with my laptop trying from the hub connection. Then all of a sudden in the afternoon it connected. The only thing I can think is that the hub got bumped and knocked something into place, the computer was directly attached to the router before all this, and worked fine, the wires are all on the A config, and all ports on router and hub were tested for failure.
Thanks anyways again; just hope whatever happened stays in functioning mode :-|

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