[c-nsp] restricting source IP for management by username

[Ed Ravin]

I have several users with access to a router.  I want to add a new
user, one who can only log into that router when he or she is connecting
from a particular host.  How can I set this up?  I have a TACACS+ server,
if that's any help, though I don't mind setting the config locally if it's
simpler.

Thanks,

	-- Ed