Which version of ESX are you using?
I've restart the mgmt-vmware service several time in a ssh session without problem.
VIC connection will be dropped, by this is normal.
This will generally solve the issue if you're coming from another system http://www.slac.stanford.edu/comp/unix/ssh_faq.html#logoff_hangs, I've seen this from time to time when restarting the management service.
VMware vExpert 2009
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