[provisioning] add `tcpdump` for network debugging
[provisioning] add `tcpdump` for network debugging

englishm/vagrant-xen,yifanz/mirage-vagrant-vms,yifanz/mirage-vagrant-vms,sjfloat/mirage-vagrant-vms,englishm/vagrant-xen,mirage/mirage-vagrant-vms,mirage/mirage-vagrant-vms,sjfloat/mirage-vagrant-vms