ip address:
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
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp4s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master br0 state UP group default qlen 1000
link/ether 18:c0:4d:61:f3:ba brd ff:ff:ff:ff:ff:ff
3: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether ee:ab:f3:da:31:3d brd ff:ff:ff:ff:ff:ff
inet 192.168.2.98/24 brd 192.168.2.255 scope global br0
valid_lft forever preferred_lft forever


route:
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         fritz.box       0.0.0.0         UG    0      0        0 br0
192.168.2.0     0.0.0.0         255.255.255.0   U     0      0        0 br0


/etc/network/interfaces:
iface enp4s0 inet manual
iface enp4s0 inet6 auto
auto br0
iface br0 inet static
bridge_ports enp4s0
address 192.168.2.98
broadcast 192.168.2.255
netmask 255.255.255.0
gateway 192.168.2.1
dns-nameservers 192.168.2.1

VM starts...
Route list changes into that:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         0.0.0.0         255.255.255.255 UH    0      0        0 vnet1
default         0.0.0.0         0.0.0.0         U     0      0        0 vnet1
default         fritz.box       0.0.0.0         UG    0      0        0 br0
link-local      0.0.0.0         255.255.0.0     U     0      0        0 vnet1
192.168.2.0     0.0.0.0         255.255.255.0   U     0      0        0 br0