Force DHCP to assign the same ip always to the same client?

Question

I'm behind a router with at least 1 client and at most 3 clients. My "main" client runs some services like Apache2 so I port forwarded in router configuration the incoming traffic to its IP address 10.0.0.2 assigned by the router's dhcp. Sometimes it happens that the routers assigns 10.0.0.3 to my main client so i have to change all the forwarding. Are there any possibilities to avoid this?

I thought about something like

ifconfig eth1 down
ifconfig eth1 10.0.0.2 up

but this doesn't help. I still have 10.0.0.3.

This doesn't work either.

dhclient -r
ifconfig eth1 down
ifconfig eth1 10.0.0.2 up

I have still 10.0.0.3 after reconnecting.

Maybe there are another solutions? By the way, this must not be a perfect solution because it's just a home network, but the target is to not change all the forwardings all the time.

Answer 1

This is called a "DHCP reservation", or sometimes "static DHCP".

How it's configured will depend on your router, but many consumer routers do have this capability.

Answer 2

Shane's suggestion should work.

Another method - say if your router is 10.0.0.1 and it starts giving out ip addresses from 10.0.0.2 onwards, you may be able to reconfigure it so the first available ip to give out is i.e. 10.0.0.10 Then you can manually specify the ip on devices 10.0.0.2 - 10.0.0.9 and it will work.