General discussion

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    Topic
  • #2095284

    DHCP Server

    Locked

    by mak1515 ·

    Hi,
    Recently, I’m trying to increase the parameter in DHPC Manager. I can’t just change the end range. So I have to recreate it. First I delete the existing IP address under local machine. Second I create a new with the same subnet mess and start range, and increase the end range to 254, 255, etc… And I received a message saying that the parameter is exceed the existing one. Is it I have to restart the Server and stop the dhcp server first, then do the recreation? Or there are some other steps that I don’t know?
    I’ll appreciate for any suggestions!

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    • #3854044

      DHCP Server

      by luiz.contador ·

      In reply to DHCP Server

      Hi,

      You are trying to put any value high then 255, If yeah, this is the problem, because the IP range go until 255, because 2^8 is 256, 0….255, What you could do is see your mask Andress if it isn’t 255.255.255.0 you could change the range for example if it was 161.83.5.255 you could use the mask andress 255.255.0.0 and the others ip could be 161.83.6.12 for example

      • #3853244

        DHCP Server

        by mak1515 ·

        In reply to DHCP Server

        I’m not trying to put the value higher than 255. My subnet mask is 255.255.255.224 what should the range be, how to calculate it? My Gateway and server ips is not 161.83.5.0 and 161.83.5.1, in this case, am I able to do what you said above? Can I just change the subnet mask to 255.255.255.0 like what you said? Thanks!

    • #3853401

      DHCP Server

      by madsg ·

      In reply to DHCP Server

      Yes I would give luiz cantador right.
      But I would not use 255.255.0.0 as subnet address but in stead 255.255.254.0 and then an IP start as:169.83.4.0
      and IP stop:169.83.5.255
      Then the machines would no that all other IP addresses is in another subnet and therefor contact the default gateway.
      While with a subnet address of 255.255.0.0 all addresses from 169.83.0.0 to 169.83.3.255 and 169.83.6.0 to 169.83.255.255
      could newer be contacted.

      Best regards
      Mads

      • #3853245

        DHCP Server

        by mak1515 ·

        In reply to DHCP Server

        Thanks, guys!

    • #3834126

      DHCP Server

      by jvohs ·

      In reply to DHCP Server

      Do all the clients still have leases? If so, and they haven’t been lost make sure and set them down to a few hours and wait until they all get new leases. Then stop and remove the DHCP service, say no to the reboot when you close the network control panel. Reapply the service pack, and reboot. Then reinstall DHCP, and create a new scope. This is the key, set the leases down before you do this, then do this on Friday after people leave. Then when people come in the next day or Monday, they all have new leases. Remember a DHCP client will not renew with a different DHCP server until 87.5% of the lease is up to prevent stuck leases. Otherwise you’ll end up with all kinds of IP conflicts. Good luck!

      • #3857653

        DHCP Server

        by mak1515 ·

        In reply to DHCP Server

        Poster rated this answer

    • #3834068

      DHCP Server

      by luiz.contador ·

      In reply to DHCP Server

      OK,
      If your mask andress is 225.225.255.224, the max number of computers that you could have is 2^5 or 32, because How we calculate the mask andress: we have 8 bits 11111111 so the 3 first bits 2^7 + 2^6 + 2^5 is 224, this is the wan bits, the rest is your lan bits 2^4 + 2^3 + 2^2 + 2^1 + 2^0 is 32, so your range must go 0 .. 32 but you have to pay attencion that the 0 and 32 do not be used, because the 0 andress is a control ip and the last ip is the broadcast ip

      I hope that this help you !!!

      • #3834066

        DHCP Server

        by luiz.contador ·

        In reply to DHCP Server

        About your question if you could use the mask 255.255.255.0 you can only if don’t have other company in your lan using the same ip range for example 161.83.4.10, and have other company from group that have the ip 161.83.4.60, because if it was the case your ip will conflit or not talk with the other

      • #3857654

        DHCP Server

        by mak1515 ·

        In reply to DHCP Server

        Poster rated this answer

    • #3833499

      DHCP Server

      by pgdkansas ·

      In reply to DHCP Server

      I agree with a great deal of what everyone has mentioned.

      Simply stated…your range is 31. (IE: 167.45.56.67 to …98)inclusive.

      to calculate 255-224 = 31 yeilds 8 subnets (255/31)

      Maybe too simply stated, but that’s the gist of it.

      Hope I helped even though it was vague.

      • #3857655

        DHCP Server

        by mak1515 ·

        In reply to DHCP Server

        Poster rated this answer

    • #3857652

      DHCP Server

      by mak1515 ·

      In reply to DHCP Server

      This question was closed by the author

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