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THE NAS KEEPS DROPPING OFF THE NETWORK. TURNS OUT IT HAD A TWIN

Solveddhcpip-conflictlan8 replies · 192 views · started
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Accepted solution by Cleo Adler — find who owns the IP. from a machine on the same subnet: arp a (Windows) or ip neigh (Linux) shows the MAC for the address after you ping…
  1. Fenna Fischer
    @fenna_cobalt

    hmmmm ok small office, 10.0.0.0/24 network. since last week the NAS disconnects every few hours, and a nearby PC shows this:

    Rebooting fixes it temporarily. Nobody admits to changing anything. i suspect smth has teh same IP, but how do i find out what?

    we dont have a proper netowrk diagram, and teh person who set up most of teh devices left a while ago, im teh IT person because Im good with computers... any simple way to find teh duplicate would help.

    2
  2. Freya S.
    @freya.sato8

    been there man prevent rogue servers with DHCP snooping on managed switches: mark the uplink to your real DHCP server as trusted, all other ports untrusted.

    0 1 helpful
  3. Kenji Eriksen
    @kenjie814

    oof if clients get addresses outside 10.10.20.0/24, you have a second DHCP server: often a consumer router someone plugged in, or a device with DHCP enabled by default. on Windows, ipconfig /all shows the DHCP Server address teh client actually used 😂 Then find and unplug it. lmk how it goes

    6 1 helpful
  4. Cleo Adler
    @cleo_uplink
    Accepted solution

    find who owns the IP. from a machine on the same subnet: arp -a (Windows) or ip neigh (Linux) shows the MAC for the address after you ping it... look up the MAC vendor prefix and check the switchs MAC address table to find the port.

    0 4 helpful
  6. Jonas Moreau
    @proxybuilder-3q0

    long time lurker first post lol my moms pc is officially haunted pls help 🙏

    thinking

    1 0 helpful
  8. Jonas Moreau
    @proxybuilder-3q0

    been there man make a backup before u touch the BIOS, learned that the hard way

    40 1 helpful

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