Proliant machine intermittent connectivity

[izus]

we run this particular server as a file server / domain controler at one of our small offices (offsite)
at first i thought this was a DNS issue.
but the more i get into this mess the more im convinced its not.
this machine resides off site so i cant physically hook up to it, unfortunitely.

the issue started the other day when employees called me saying they lost connection with the file server.
i tried to remote into the server with no luck.
tried to ping its domain name, nothing, pinged its ipaddress, nothing.
then i had someone who was at that physical office ping the server, he tried to ping it.. still nothing...
not ipaddress of domain name
i had the guy physically hard shut down the machine and reboot it....
it rebooted and worked fine for about 2 hours then BAM same thing happened.

i dont know where to go from here other than driving to that office 250 miles away and hooking a monitor to that box to see whats up.
they can ping everything else no problems they just cant ping that server.
ohh
those guys still can access the VPN's to ping the main server with domain names.
does not this mean the DNS is still working?
plus they can still access their mail which resides 250 miles away on another exchange server.

i dont even know where to begin looking for issues with this problem.
please help
thank you,

[izus]

i replaced the network card, still same issue.
all the clients still have dhcp through this server however can not ping it.

[izus]

the server cant ping the router or any other local machine on this local network but can ping google.
im so confused

[Glenn Matthys]

Is there any firewall software installed? That may be the culprit. Is the ILO still accessible?

[izus]

no firewall was installed.
what is the ILO?