Make sure the interface you are running on is configured with the same address as the listen-address in your dnsmasq.conf.

Configuring with ip

sudo ip addr add dev enp3s0 192.168.70.1/24

And my dnsmasq config as follow

keep-in-foreground

# Disable DNS
port=0

# Setup DHCP
log-dhcp
interface=enp3s0
listen-address=192.168.70.1
dhcp-range=192.168.70.2,192.168.70.255,72h
dhcp-option=option:router,192.168.70.1

To see what happens on the interface, tcpdump is always helpful

# tcpdump --interface=enp3s0

References

  • man dnsmasq