Vagrant and network interfaces

My Vagrant file does not look like it is doing anything special with networking:

config.vm.box = "centos/7"config.vbguest.installer_options = { allow_kernel_upgrade: true }config.vm.network :private_network, type: "dhcp"config.vm.hostname =  name

Why do my VMs have 3 eth adapters?

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000    link/ether 52:54:00:4d:77:d3 brd ff:ff:ff:ff:ff:ff    inet 10.0.2.15/24 brd 10.0.2.255 scope global noprefixroute dynamic eth0       valid_lft 82200sec preferred_lft 82200sec    inet6 fe80::5054:ff:fe4d:77d3/64 scope link        valid_lft forever preferred_lft forever3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000    link/ether 08:00:27:e8:73:39 brd ff:ff:ff:ff:ff:ff    inet 192.168.56.17/24 brd 192.168.56.255 scope global noprefixroute dynamic eth1       valid_lft 387sec preferred_lft 387sec    inet6 fe80::a00:27ff:fee8:7339/64 scope link        valid_lft forever preferred_lft forever4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000    link/ether 08:00:27:8e:cc:e5 brd ff:ff:ff:ff:ff:ff    inet 192.168.56.18/24 brd 192.168.56.255 scope global noprefixroute dynamic eth2       valid_lft 600sec preferred_lft 600sec    inet6 fe80::a00:27ff:fe8e:cce5/64 scope link        valid_lft forever preferred_lft forever