vagrant ssh -c not returning

[xenoterracide]

for some reason this never returns, it does if I run it on my host shell directly though

    config.vm.provision :host_shell, run: "always"  do|s| # evil hack to deal with stupid route problem
            s.inline = "vagrant ssh oracle -c 'setsid ping -q -i 5 172.28.128.3'"
    end