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creating a new subnet

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  • creating a new subnet

    We have a major issue.. we are running out of IP addresses due to the amount of personal printers in our office. they are taking up about 40 ip addresses.

    We want to add a second subnet 10.0.x.x But are unsure how to do it.
    Are there any suggestions such as equipment or design?

    Do we need a second router or a better router than a Cisco 1721?

    thanks to all who respond

  • #2
    Re: creating a new subnet

    I think we need some more detail -- current subnet, method of assigning IPs etc.
    The simplest solution would be to create a "supernet" by modifying the subnet mask suitably but a lot depends on your setup
    Tom Jones
    MCT, MCSE (2000:Security & 2003), MCSA:Security & Messaging, MCDBA, MCDST, MCITP(EA, EMA, SA, EDA, ES, CS), MCTS, MCP, Sec+
    IT Trainer / Consultant
    Ossian Ltd

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    • #3
      Re: creating a new subnet

      OK it is a win 2k3 environment

      we use DHCP range from 202.x..xx.50 - 202.x.xx.200

      this is not counting servers or other appliances.
      we have 100 users and 2 sattellite offices. each with their own subnets and vpns that talk back to our network.

      we have a cisco asa 150?? firewall and the cisco 1721 as our router

      Does this help?


      • #4
        Re: creating a new subnet

        Originally posted by mlabs View Post
        we use DHCP range from 202.x..xx.50 - 202.x.xx.200
        Am I correct in understanding that you're assigning publicly routable IP addresses to your LAN machines?
        Wesley David
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        • #5
          Re: creating a new subnet

          Which, if you are, is perfectly acceptable. Unorthodox and unusual, but acceptable. Before RFC 1918 everyone used publicly routable ip addresses on their internal network. RFC 1918 was put in place to stave off the exhaustion of the IPv4 address space, not to address security issues. The fact that there are security benefits to using RFC 1918 addresses internally was purely an unforeseen benefit of the RFC. Make sure you have a good strong firewall policy in place and only allow external to internal traffic where it's needed (inbound email, etc.).