$ ps ax | grep dnsmasq
  894 ?        S      0:00 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvirt_leaseshelper
  895 ?        S      0:00 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvirt_leaseshelper
  990 pts/0    S+     0:00 grep --color=auto dnsmasq
 1891 ?        S      0:00 /usr/sbin/dnsmasq -x /run/dnsmasq/dnsmasq.pid -u dnsmasq -r /run/dnsmasq/resolv.conf -7 /etc/dnsmasq.d,.dpkg-dist,.dpkg-old,.dpkg-new --local-service --trust-anchor=.,19036,8,2,49AAC11D7B6F6446702E54A1607371607A1A41855200FD2CE1CDDE32F24E8FB5

$ cat /etc/dnsmasq.d/network-manager
# Tell any system-wide dnsmasq instance to make sure to bind to interfaces
# instead of listening on 0.0.0.0
# WARNING: changes to this file will get lost if network-manager is removed.
bind-interfaces

$ cat /etc/dnsmasq.d/libvirt-daemon
bind-interfaces
except-interface=virbr0

$ sudo netstat -tunap | grep dns
tcp        0      0 192.168.100.1:53        0.0.0.0:*               LISTEN      894/dnsmasq
tcp        0      0 127.0.0.1:53            0.0.0.0:*               LISTEN      1891/dnsmasq
tcp6       0      0 ::1:53                  :::*                    LISTEN      1891/dnsmasq
udp        0      0 192.168.100.1:53        0.0.0.0:*                           894/dnsmasq
udp        0      0 127.0.0.1:53            0.0.0.0:*                           1891/dnsmasq
udp        0      0 0.0.0.0:67              0.0.0.0:*                           894/dnsmasq
udp6       0      0 ::1:53                  :::*                                1891/dnsmasq

$ ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: enp2s0f2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
    link/ether 60:45:cb:b3:a0:be brd ff:ff:ff:ff:ff:ff
3: wlp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 3c:a0:67:15:d9:13 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.109/24 brd 192.168.1.255 scope global dynamic wlp3s0
       valid_lft 40680sec preferred_lft 40680sec
35: br0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 82:fa:f1:e1:ee:cb brd ff:ff:ff:ff:ff:ff
37: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 52:54:00:1c:12:1b brd ff:ff:ff:ff:ff:ff
    inet 192.168.100.1/24 brd 192.168.100.255 scope global virbr0
       valid_lft forever preferred_lft forever
38: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:1c:12:1b brd ff:ff:ff:ff:ff:ff
39: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master virbr0 state UNKNOWN group default qlen 1000
    link/ether fe:54:00:a0:2e:44 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc54:ff:fea0:2e44/64 scope link
       valid_lft forever preferred_lft forever

$ ip route
default via 192.168.1.1 dev wlp3s0 proto static metric 600
169.254.0.0/16 dev wlp3s0 scope link metric 1000
192.168.1.0/24 dev wlp3s0 proto kernel scope link src 192.168.1.109 metric 600
192.168.100.0/24 dev virbr0 proto kernel scope link src 192.168.100.1

$ brctl show
bridge name bridge id       STP enabled interfaces
br0     8000.000000000000   yes
virbr0      8000.5254001c121b   yes     virbr0-nic
                            vnet0