1

I want to change from 255.255.255.0 to 255.255.252.0 because we are out of addresses. Is it as simple as just changing the subnet on servers, firewall, gateway. Then change the scope and make sure all other computers and printers, etc. get the subnet changed?

Thanks for your help,

Paul Wagner

7 Spice ups
2

The simple answer is yes. As long as you use dhcp for your workstations they will get the updated settings as well.

2 Spice ups
3

Yes, the Superscope needs to have the subnet mask set to 255.255.252.0 and then setup your scopes under the superscope.

4

Yep!

My question would be is .252.0 big enough? that’s 1000 IP addresses. Don’t really want to be going through this again do you?

5

Thats all that needs to be changed in the scope is the subnet correct? I feel like I know but, I dont want to change everything and find it doesnt work.

6

Yes, that will be plenty of addresses, by the time we would need more I will be gone or dead.

7

You feel as though you know, because you understand how it works and are correct.

8

Correct, thats all you need to change in the scope. What device is handing out dhcp? Server or firewall? If you have the ability to wait until everyone is off the system, I would.

9

Yes, but remember that anything with a static address will need to be updated and they don’t grab DHCP. When we did ours, we set the lease to expire after two hours and left it for a day. The next morning everyone turned in and logged on no problem.

You will notice items in your network on static addresses that you didn’t remember you set up, so for a few weeks, assume that you need to look at the IP address.

1 Spice up
10

Server hands out DHCP. We plan on doing it on a Saturday when everyone is out of the building.

When you say static ips need to be updated do you mean they have to have subnet changed and then shutdown and restarted?

11

By changing the subnet of your network, some devices that are statically set will no longer be able to be reached by the devices on the new subnet, they will have to be modified to match the new subnet in order for those devices to be reached again, printers, servers, etc.

12

Right, change the subnet on all static devices. Those on DHCP will not be affected unless I do not change the lease time to expire sooner.

Maybe a dumb question but we use 192.168.1.0 now, when changing the subnet I dont have to change to 192.168.0.0?

I just make it a /22 and then change the subnet .

I think i am talking myself in circles worrying about screwing it up. I just want more IPS and be done with it.

I dont know if I change 192.168.0/22 if it screws up the ips we already are using that are 192.168.1.1-.254.

13

Oh dear Lord…

14

Oh dear lord what? I am not a Superior network guy. Trying to get this done and dont want to mess it up. Never have done it before.

15

Same, I’m just trying to help. I’m actually still going to school! I learn more with every post I read and respond to.

16

If you are currently 192.168.1.0/24 and want to move to /22, your new network becomes 192.168.0.0/22.

Your usable IP addresses are 192.168.0.1-192.168.3.254.

I believe that BrianWhelton is shaking is head at the post above his, which is quite wrong about your usable IPs.

This is basic networking (subnetting). There is nothing advanced about it.

17

Like I mentioned, still in class and just trying to help, and learn at the same time. My apologies if my information was incorrect, and thank you for the correction. I will be sure to go through the subnetting section again!

18

Sorry for the double post, I see where I went wrong! Thanks again for the correction.

19

I took classes a long time ago and never really touched on subnetting, so reading up on it I thought I would ask some people who might know instead of fudging it all up. Thank you for everyones help.

20

We only went over it briefly as well, but I have a book at home that goes more into detail about it, I’ll read over it over the next few days. I just did my math wrong when calculating the network you were using,