ISC DHCP Server configuration for multiple pools on Ubuntu 18.04

[pvs]

Let me clarify.

I want to setup DHCP server to issue IP addresses in different networks, 
let us say

VLAN1: Network1: 192.168.40.0/24

VLAN2: Network2: 10.10.10.0/24

VLAN3: Network3: 192.168.37.0/24

Network4:

etc -

----upto 100 Class C Networks

My DHCP Server network is configured with IP address 192.168.40.X

This DHCP server has to receive DHCP requests from  clients sitting in 
different VLAN.

Layer 3 Switch providing inter VLAN routing is configured with DHCP 
relay to  forward DHCP requests to this 192.168.40.X address

Clients configured for VLAN1 are getting IPaddresses from DHCP server, 
not all other clients sitting in other VLANs


Regards,

Vishnu Sankar




On 23-02-2023 15:06, Jeffrey Walton wrote:
> 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

-- 
Regards,

पं. विष्णु शंकर		P. Vishnu Sankar
टीम लीडर                Team Leader-Network Operations
सी-डॉट                  C-DOT
इलैक्ट्रॉनिक्स सिटी फेज़ I    Electronics City Phase I
होसूर रोड बेंगलूरु          Hosur Road Bengaluru – 560100
फोन  Ph                91 80 25119466
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