implement new network setup, DHCP WAN address with additional static subnet

Started by skyjam, February 22, 2022, 11:49:56 AM

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Hi there

I need to setup an additional site and I have the following requirements:

  • The IP address range will be routed through a static IP address that will be assigned to the router with MAC reservation.
  • Behind this static IP address, the subnet for the IP range is implemented by the customer (5 public IP addresses are available in this subnet).

I get a static range /29, (i.e. 55.66.77.88) whereas:

  • .88 => the first address will be the network address
  • .89 => the second address is the local gateway
  • .90-94 => the 3rd to 7th address can be used as desired
  • .95 => the last address is for broadcast

How do I need to setup opnSense to use this subnet with a private LAN subnet and NAT routing?
I guess the WAN is simply DHCP.
Do I need to add Virtual IPs fot the static subnet?

Thanks for your hints!

This already assumes that a subrange like /30 or /29 can be assigned using DHCP. Is that supported by DHCP in the first place ?
OPNSense on Elite Edition Intel N100 - Crucial 16G DDR - Lexar NM620 512GB

Quote from: HappyOpnSense on February 24, 2022, 02:45:34 PM
This already assumes that a subrange like /30 or /29 can be assigned using DHCP. Is that supported by DHCP in the first place ?
No, the subnet will not be assigned using DHCP. Only the IP address of the router will be assigned. This IP is not part of the subnet!

It is like this:

     WAN / Internet
            |
            |  Cable-Provider
            |
      .-----+-------.
      |  HFC Modem  |  (Bridge)
      '-----+-------'
            |
            |  WAN
            |
      .-----+------.   <--- IP assigned by ISP/DHCP
      |  Router    |
      '-----+------'
            |
            |  Public IP subnet (/29)
            |
      .-----+----.
      | opnSense |
      '-----+----'


I want to combine the router and the opnSense in one...