How to setup the dnsmasq

dnsmasq

Manage the DNS server, DHCP server easily dnsmasq

lstlisting caption= /etc/dnsmasq.d/br_tap.conf

interface=br_tap

listen-address=192.168.0.1

bind-interfaces

bogus-priv

dhcp-range=192.168.0.2,192.168.0.250,255.255.255.0,24h

server=10.32.192.11

server=10.32.193.11

no-resolv

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After install and setup this package, each VM instance would use the host's "hosts" (/etc/hosts) file for resolving the DNS query which is requested from in it.

In order to make it work properly, you should change the systemd-resolved configuration of your VM instances. systemdresolv

List of DHCP clients

lstlisting caption= List of dhcp clients ,style=bash

cat /var/lib/misc/dnsmasq.leases

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DHCP client connection management

When a new DHCP client gets an address from the dnsmasq service, you may want to bind a new DNS name to it.

In order to do that, you should know when a new client gets an address.

Fortunately, the dnsmasq will execute a script for handling a new client.

lstlisting caption= Configuration ,style=bash

. . .

# Run an executable when a DHCP lease is created or destroyed.

# The arguments sent to the script are "add" or "del",

# then the MAC address, the IP address and finally the hostname

# if there is one.

dhcp-script=/usr/local/bin/dnsmasq.dhcp

. . .

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Each client should send their client Id, therefore, the client id must be revised.

client file must be updated to use the mac address for the client id

lstlisting caption= /etc/netplan/somefile.yaml ,style=yaml

network:

version: 2

ethernets:

ens3:

dhcp4: true

dhcp-identifier: mac

lstlisting