This is a problem with vagrant 1.9.3:
You can upgrade to the latest version to stop getting this error or,
To make it work with this version, specify host ip in the Vagrantfile in every port forwarding command:
config.vm.network :forwarded_port, guest: 7050, host: 7050, host_ip: "127.0.0.1" # fabric orderer service
config.vm.network :forwarded_port, guest: 7051, host: 7051, host_ip: "127.0.0.1" # fabric peer service
config.vm.network :forwarded_port, guest: 7053, host: 7053, host_ip: "127.0.0.1" # fabric peer event service
config.vm.network :forwarded_port, guest: 7054, host: 7054, host_ip: "127.0.0.1" # fabric-ca service
config.vm.network :forwarded_port, guest: 5984, host: 15984, host_ip: "127.0.0.1" # CouchDB service
Vagrant should now work.