$ sudo lsof -i UDP:53
COMMAND  PID   USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
dnsmasq 3461 nobody    6u  IPv4  27341      0t0  UDP poste1.local:domain 

$ ps -p 3461 -f
UID        PID  PPID  C STIME TTY          TIME CMD
nobody    3461     1  0 11:00 ?        00:00:00 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --dhcp-script=/usr/lib/libvirt/libvirt_leaseshelper

/var/lib/libvirt/dnsmasq/default.conf

##WARNING:  THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE
##OVERWRITTEN AND LOST.  Changes to this configuration should be made using:
##    virsh net-edit default
## or other application using the libvirt API.
##
## dnsmasq conf file created by libvirt
strict-order
pid-file=/var/run/libvirt/network/default.pid
except-interface=lo
bind-dynamic
interface=virbr0
dhcp-range=192.168.122.2,192.168.122.254
dhcp-no-override
dhcp-leasefile=/var/lib/libvirt/dnsmasq/default.leases
dhcp-lease-max=253
dhcp-hostsfile=/var/lib/libvirt/dnsmasq/default.hostsfile
addn-hosts=/var/lib/libvirt/dnsmasq/default.addnhosts

virsh -c qemu:///system net-edit default