ISC DHCP Server configuration for multiple pools on Ubuntu 18.04

[Jeffrey Walton]

On Thu, Feb 23, 2023 at 4:25 AM pvs via ubuntu-users
<ubuntu-users at lists.ubuntu.com> wrote:
>
> I am setting up new ISC DHCP Server (version 4.3.5) on Ubuntu 18.04. This system is configured with single NIC.
> Need to configure DHCP server for multiple leases on different Class C networks.
>
> Googled and tried multiple ways, none of them worked.
>
> Contents of  /etc/dhcpd/dhcpd.conf file
>
> authoritative;
>
> shared-network companynetwork {
> subnet 192.168.40.0 netmask 255.255.255.0{
>  range 192.168.40.150 192.168.40.160 ;
> option domain-name-server 8.8.8.8;
> option subnet-mask 255.255.255.0;
> option routers 192.168.40.1;
> option broadcast-address 192.168.40.255;
> default-lease-time 600;
> max-lease-time 7200;
> }
> subnet 10.10.10.0 netmask 255.255.255.0{
>  range 10.10.10.10 10.10.10.20;
>  option subnet-mask 255.255.255.0;
>  option routers 10.10.10.1;
>  option broadcast-address 10.10.10.255;
>  default-lease-time 600;
>  max-lease-time 7200;
> }
> subnet 192.168.37.0 netmask 255.255.255.0{
>  range 192.168.37.131 192.168.37.140;
>  option subnet-mask 255.255.255.0;
>  option routers 192.168.37.1;
>  default-lease-time 600;
>  max-lease-time 7200;
> }
> }
>
> Contents of/etc/netplan/50-cloud-init.yaml    -----   network configuration file
>
> network:
>     version: 2
>     ethernets:
>        ens160:
>                addresses:
>                    - 192.168.40.29/24
>                gateway4: 192.168.40.1
>                nameservers:
>                    addresses: [8.8.8.8]
>
> With the above configuration, DHCP addresses get issued from192.168.40.0 pool only, not from other pools.
>
> Any help is greatly appreciated

It sounds like you want one NIC to receive multiple IP addresses.
That's called multihomed.

See discussions like
https://serverfault.com/questions/363695/using-dhcp-with-multi-homed-nics
.

Jeff