Static IP working but resetting to Dynamic Over Night

[genesus]

This week at work we migrated our network to a dedicated T1 hard line, which really rocks since there are only four of us.

I migrated all of our servers to a cisco switch and updated the /etc/network/interfaces to look like this

##NEW CONFIG 
# The loopback network interface

auto lo
iface lo inet loopback

# The primary network interface

auto eth5
iface eth5 inet static
address 216.81.49.XXX
netmask 255.255.255.248
gateway 216.81.49.249
network 216.81.46.248
broadcast 216.81.49.255

When I do this and run /etc/init.d/networking start everything works flawlessly, I receive the static ip address and our servers work perfectly; however, sometime over the evening the ip address resets to a dynamic ip, just as if I had the following:

allow-hotplug eth5
iface eth0 inet dhcp

In the morning to fix the issue all I have to do is run
/etc/init.d/networking stop
/etc/init.d/networking start

and the correct static ip is running again.

Does anyone have any ideas of what could be causing this issue? It's sort of frustrating to have server access go down in the middle of the night and have to do this first thing every morning.

Does it have something to do with the included broadcast line? I've browsed some other interfaces files and not encountered it yet; however, I included it because it was provided by the line.

[athlon_crazy]

atleast you should get something from your /var/log/messages do you?

[genesus]

Nothing from /var/log/messages seems amiss, I think I've isolated the problem and will open a new thread to deal with it.

[coopstah13]

allow-hotplug eth1
iface eth1 inet static
address 10.100.44.77
netmask 255.255.248.0
broadcast 10.100.47.255
gateway 10.100.40.1

this is all i need for static ip on my network

but it seems like something else is wrong, since the configuration works, but something makes it reset back to dhcp afterwards

[genesus]

solved,

the line provided flushed the line and updated the software on the gateway...problem has not recurred.