none
Running low on IPs...what are our options? RRS feed

  • Question

  • We're almost out of IP addresses on our main subnet 192.168.0.x/24. DHCP servers have a lease duration of 1 hour, do not want to lower this anymore.

    I see two possible solutions here (open to more solutions!)

    a) Change the subnet mask on the 192.168.0.x subnet to allow more hosts. This is the obvious solution but if you read on I think this will be too disruptive.
    b) Move the client computers to a new subnet that can accommodate more hosts. The clients are using up most of the IP addresses and will continue to grow.


    Here's a brief snapshot of what's on this subnet:
    192.168.0.1/24 - Firewall (SonicWall NSA 3500).
    192.168.0.2/24 - DC1 (Server 2008R2, DHCP, DNS).
    192.168.0.3/24 - DC2 (Server 2008R2, DHCP, DNS).
    192.168.0.5/24 - 192.168.0.30/24 - Server range (all statically assigned IPs).

    Exclusion ranges from DHCP servers (all with static IPs).
    192.168.0.100/24 - 192.168.1.125/24 - Ethernet printers.
    192.168.0.250/24 - 192.168.0.254/24 - Switch management range.

    We have more things with static IPs like UPS, CCTV system, phone systems etc...

    I think option a) will cause chaos and would be nice to move the clients away from everything else? I'll need to make both subnets routable. Both subnets will be connected to the same switches so I'll stop DHCP servers on current 192.168.0.x subnet then create a new DC for the new subnet to provide DHCP, DNS etc..


    Main site switches:
    192.168.0.x/24 - Clients, servers, printers, management. <-- this is the problem subnet
    192.168.1.x/24 - Wi-Fi (guns)

    Hyper-V Switches (not routable to main site switches):
    192.168.100.x/24 - iSCSI-1
    192.168.101.x/24 - Live Motion
    192.168.102.x/24 - Heart Beat + Switch management
    192.168.105.x/24 - iSCSI-2

    Remote sites (connected with site-to-site VPN)
    192.168.98.x/24  Remote Site
    192.168.99.x/24  Remote site

    We have more subnets but these are the only ones worth mentioning.

    Friday, February 19, 2016 10:03 AM

Answers

  • Hi Klevin,

             According your description,you could deploy VLAN on your network with  a  Router/L3 switch.

             1.>> We have more things with static IPs like UPS, CCTV system, phone systems etc...

                Put the devices have same properties in the same VLAN,make it easy to manage.For more information about VLAN configuration,please contact the vendor.

             2.>> Both subnets will be connected to the same switches so I'll stop DHCP servers on current 192.168.0.x subnet then create a new DC for the new subnet to provide DHCP, DNS etc..

                Please create scopes for the different VLANs and configure the DHCP relay agent point to you DHCP server on the router/L3 switch ,so the relay agent for each VLAN  send all to the DHCP server having the scope for it,. Clients should then get the lease for the correct scope based on the relay agent.And you don’t need to create DC for every new subnet.

     

            

      Best Regards,

    Cartman


    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Monday, February 22, 2016 6:53 AM

All replies

  • 192.168.1.0/24 is already in use, so extending 192.168.0.0 subnet will require moving wi-fi devices to a different subnet. And, since you need to move something anyway, then you may as well allocate a new, larger, subnet for the clients. To minimize the changes, you can leave servers and printers in 192.168.0.0, but make sure you have enough routing/L3 switching capacity to route traffic between clients on the new subnet and the servers.

    Gleb.

    Friday, February 19, 2016 10:30 AM
  • Hi Klevin,

             According your description,you could deploy VLAN on your network with  a  Router/L3 switch.

             1.>> We have more things with static IPs like UPS, CCTV system, phone systems etc...

                Put the devices have same properties in the same VLAN,make it easy to manage.For more information about VLAN configuration,please contact the vendor.

             2.>> Both subnets will be connected to the same switches so I'll stop DHCP servers on current 192.168.0.x subnet then create a new DC for the new subnet to provide DHCP, DNS etc..

                Please create scopes for the different VLANs and configure the DHCP relay agent point to you DHCP server on the router/L3 switch ,so the relay agent for each VLAN  send all to the DHCP server having the scope for it,. Clients should then get the lease for the correct scope based on the relay agent.And you don’t need to create DC for every new subnet.

     

            

      Best Regards,

    Cartman


    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Monday, February 22, 2016 6:53 AM