IP address Range increase-Dhcp- Windows server 2019

[sshabir]

Hi All,

I am in an interesting situation where I am trying to expand my Ip range with Rm Networks.

We currently have an ip range set to:

10.141.80.0-10.141.81.254/23 (255.255.254.0)

The ip range has been increased to 10.141.83.254/22 (255.255.252.0)

Rm Networks says the router is set up with /22 subnet but my dhcp server is set up with /23 (255.255.254.0)subnet

I have created another scope with the below:

10.141.82.1-10.141.83.254 /23 but it is not working. we are using a Windows Server 2019. I reserved one of the ip address to use the newly created scope ip address but it was connected

to wi-Fi but was not connecting to any of the websites or apps.

I would like to use the scope settings if possible 10.141.82.1-10.141.83.254 /23.

It should be possible if the dhcp server is working fine with 10.141.80.1-10.141.81.254 /23?

Any help or advice is much appreciated as I don't want to lose any reserved ip setting while changing any of the settings.

Thanks in advance.

[Jcx500]

Have you got vlans setup, i would recommend you set them up if you don't

 

How is your network setup? and what is your router is it a layer 3 switch or a dedicated router such as a Cisco one

Edited March 19, 2021 by Jcx500

[Davit2005]

I'm sure just creating an additional scope will not work as you are creating an additional network/subnet. Devices in that additional scope/subnet will not be able to talk to other devices in other networks unless you have some form or router/layer3 switch which is able to route traffic between the 2 subnets.

 

I must admit I am unfamiliar with setups such as these though, most experience is with having core switches etc.

 

So if the RM router is in scope 1 devices in scope 2 will not be able to communicate with it as they will not know how to get to it, they are logically seperated.

 

But yes some more info would help.

Edited March 19, 2021 by Davit2005

[sshabir]

The router has always been using /22 mask but the dhcp server is setup to use /23 mask. By using /23 mask it works fine with current scope set up.

I did try to expand the current dhcp scope using the below but got an error message:

Start: 10.141.80.64

End-10.141.83.254

Subnet Mask-255.255.254.0 (Grayed out)

Error message after applying the setting: The specified range either overlaps an existing range or is not valid.

AR129 Router details:

https://www.router-switch.com/pdf/ar129-datasheet.pdf

Many Thanks

[Jcx500]

Is the AR129 acting as your core router ? or a gateway to your ISP?

[paulellam]

I extended my range in the autumn, I went from 255.255.255.0 to 255.255.252.0 so I basically reset up the whole scope, de-authorised and re-authorised re added the reserved scope etc. Changed the subnets on RM router was done first then I changed switches n other active bits of kit., then servers, then set up the new DHCP scope. Only other devices like static printers to change subnet on then. This is a short explanation due to lack of time lol. Also the above was a temp measure until better switches are procured in new budget for our vlans etc Edited March 19, 2021 by paulellam

[sshabir]

I was trying to avoid that possibility if i could as it does require a lot more work. How long did it take you and and advice if you were to redo it again? Thanks

[sshabir]

@Jcx500- The AR129 is a router with gateway but i have asked to confirm with Rm.

[Jcx500]

Ok, is your new subnet set on your switches?

[paulellam]

With correct planning It did not take long, make sure you can access all devices that have static IP,S, make sure you can get into every switch, active device anything that will need the subnet changing,. pm if you need to do

[sshabir]

It is set up on the Router but not on the switches.

[sshabir]

Reply from RM:

 

Please be informed that the router is the gateway to the ISP and we did not understand what you meant by core router.

 

As I informed earlier, the router will routes all the networks which comes under the network 10.141.80.1/22 (255.255.252.0).

 

As per your update, the current DHCP server is set to release the IP ranges from 10.141.80.64 to 10.141.81.254. This network is 10.141.80.1/23 which is under the main network 10.141.80.1/22. So, there will not be any connectivity issue.

 

- - - Updated - - -

 

Thanks for your help!

[Davit2005]

It is set up on the Router but not on the switches.

 

In that case if you were to use vlans depending if the router/switches supported it you could get the router to do the routing between the subnets/vlans (sort of router-on-a-stick). How this is achieved to get traffic routing between the subnets would depend on the router/firewall.

 

It would be ideal to setup vlans in any case, although a /22 (1022 usable addresses) is not really that big it is getting there and would enable you to segregate for security and stability but that is a big step by the sounds of it for you.