How do I pick the right IP for my Linux server… any tips?

General Forum
1

I’ve got some basic networking knowledge but not enough to feel confident about picking the right IP for my Linux server. I’m setting it up as a web server, and I think it makes sense to give it a static IP. From what I understand, the IP should be outside the DHCP range to avoid conflicts.

Here’s my situation: my subnet mask is 255.255.255.0, so my IP range is .0 to .255. The DHCP range on my router is .2 to .253. The .0 is reserved for the network, .1 is taken by the router, and .255 is for broadcasting (I think?).

Does that leave me with only .254 for static devices? That feels way too limited if I want multiple static devices. Am I misunderstanding something here? Any advice would be really appreciated. Thanks in advance!

2

You’re assuming the DHCP range can’t be changed, but it can. You can adjust it to fit your needs as long as it stays within the limits of your subnet. For example, you could extend your subnet to /23 (255.255.254.0), which would expand your range from [x.x.0.1 - x.x.0.255] to [x.x.0.1 - x.x.1.255]. That gives you a lot more IPs to work with.

If you do that, you could keep the current DHCP block and still have plenty of room for static devices.

3

@Asher
Wow, that’s interesting! I was just thinking about whether I could shrink the DHCP range instead. Is there any advantage to extending the subnet versus just making the DHCP range smaller? Thanks so much for the quick response—it’s amazing to get help like this!

4

@Brandy
It depends on your network setup. If you don’t expect to have more than 255 devices, it’s totally fine to shrink the DHCP range and stick with /24. Just reserve as many static addresses as you need outside of the reduced DHCP range.

Networking can be tricky to visualize, but you’re on the right track. Keep at it, and it’ll all make sense soon!

5

@Asher
Thanks for the advice! I’m going to shrink the range a bit :blush:

6

Could the problem just be with how my DHCP range is set up? Maybe I should make the range smaller?

7

If your router supports it, you can set static allocations within the DHCP range. You just need to configure it on the router side instead of manually assigning it on the server.

A good tip is to pick something easy to remember, like starting all servers at .200 and going up from there.