usage of ifconfig

["J.Hwan.Kim" <j.hwan.kim99@gmail.com>]

Hi, everyone

When I change IP address and netmask via "ifconfig",
the netmask is set incorrectly.

For example, when I command in shell
"ifconfig netmask 255.255.255.0 70.7.44.102",
the IP address 70.7.44.102 is set correctly,
but the netmask is set to 255.0.0.0.

Why does this case happen?

Because I want to change the network enviroment in
my application program,
I use the command ifconfig with system() function.

Any hint will be helpful to me.

Thanks in advance.

Best Regards,
J.Hwan Kim