Why is it that when I use ifconfig cmds to set eth0, then reboot, they are all gone.

Well, what dist. and version are you using? Maybe I can help.

I am using Linux 7.3, all Hardware is on HCL, and if I use DHCP from my Router works fine, but when I select static and then use the ifconfig eth0 xxx.xxx.xxx.xxx netmask xxx.xxx.xxx.xxx
route add default gw xxx.xxx.xxx.xxx
Is their a command that I must use to save this, because when I reboot or shutdown, then all the ip's are gone.

/etc/sysconfig/networking/devices/ifcfg-eth0

Ok, so do I have to manually edit the file, to reatin those IP settings, if so then aint the ifconfig commands useless

Well, ifconfig is far from useless, but you are expecting your hardware to remember settings when the power is off. It ain't gonna do that.

If you want specific settings set every time you boot, you can always add the commands to your /etc/rc.d/rc.local file. rc.local is run at the end of every boot, so saving your ifconfig commands in that file will set your card every time you boot.

An alternative would be to look into the file where the network is originally set up. In Slack that is the /etc/rc.d/rc.inet1 file, but I'm not sure if Red Hat uses the same thing (I'm assuming that by "Linux 7.3", you mean Red Hat 7.3). You could make the changes to the appropriate ifconfig commands there