Description of Problem:

#ifup eth0
ipcalc: bad ip address: 5000.4000.30.1
ipcalc: bad ip address: 5000.4000.30.1
ipcalc: bad ip address: 5000.4000.30.1
arping unknown host 5000.4000.30.1
Error, some other host already uses address 5000.4000.30.1

Now, this is an error on multiple levels -- neat should not allow blatantly
invalid IP addresses, and the scripts are returning that this address is
already in use. :)


How Reproducible:

Always

Steps to Reproduce:
1. Set an invalid IP address in neat when configuring an Ethernet interface 
2. Note that neat accepts it as valid, but you have to close the program to
write the configuration.
3. Attempt to start the interface, and note the errors.

Actual Results:

IP address was accepted, and there was an attempt to start the interface.

Expected Results:

At the very least, neat should not accept blatantly invalid IP addresses,
and the scripts should not return that an invalid IP address is already in use.

Additional Information: