Host is down

[FRANCISCO IACOBELLI <FIACOBELLI ibersis cl>]

Hello.

When i ping to a specific machine, i get the message: "Host is Down" what
are the possible causes?.
I think one is, of course that the host i am "pinging" to is down, but how
about the network card?, or maybe a router problem?... are those possible
causes?, what other weird cause comes to mind?

thanks .

Fid