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DHCP strangeness...

Discussion in 'Tech Talk' started by aspartz, May 18, 2005.

  1. aspartz

    aspartz

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    In the process of upgrading my firewall this weekend I noticed somethin strange.

    When I connect my workstation directly to the cable modem, DHCP returns an IP of 204.x.x.x/24. (I got this from ipconfig)

    When I connect my linux box (firewall) up to the cable modem, the returned IP is 63.x.x.x/22. (I get this from ifconfig).

    This seems strange to me. Which is correct?

    ARS
     
  2. HerrGlock

    HerrGlock Scouts Out CLM

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    They may be both correct.

    Can you connect outside with either machine when it is connected? If so, they may have a DHCP server that answers WIN calls and another that answers other than WIN. Yes, there is a difference.

    Have you waited a while and tried it again? It may be going off MAC address and giving the same IP range to the same MAC address.

    DanH
     

  3. aspartz

    aspartz

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    I talked to the ISP today. Both are correct. Apparently, even though I release the DHCP lease, that IP is still associated with a given MAC address for the original period of the lease. They just happen to have a disparate collection of IP's issued to them.

    I didn't ask if they supported IPv6 yet ;f

    ARS