[SOLVED] Changing Routers DHCP Addresses

[servalan]

Hi all. I recently replaced my ASUS AC66U with an ASUS AX82U. The DHCP upper and lower addresses for the 66U were 192.168.1.2 and 192.168.1.250. This was so I could give my HP 7740 the static address of 192.168.1.251. But the 82U addresses default to 192.168.50.2 and 192.168.50.255 which is a format I've never encountered before. If I manually set them back to 192.168.1.XX will the router crash? My HP won't let me change it's address to 192.168.50.XX. Any thoughts appreciated.

 

[Ralston18]

Does the following User Manual match your router?

https://manuals.plus/asus/asus-ax5400-dual-band-wi-fi-router-rt-ax82u-manual

[Do verify that I found the correct User Manual.]

Part of the problem may be that you are using an Asus website for router management.

Are you able to access the route admin functions via a browser by using 192.168.50.2?

FYI (for example):

https://www.support.com/how-to/how-to-set-up-an-asus-router-10143

Log into the router as admin and check all of the configuration settings.

You should be able to change the 82U router's default setting to 192.168.1.2 etc..

= = = =

Also: what error message or what pop-up menu choice blocks your access to the HP's network configuration screens?

 

[servalan]

Yes that's the manual. Thanks Ralston. Appreciate the info and the very quick response. I'll give it a try.

 

[gggplaya]

Just log into your asus router and click on LAN. Set the router's own IP address to 192.168.1.1 and the DHCP range should automatically match that range upon reboot.

 

[servalan]

Thanks much!

 

[Ralston18]

Just log into your asus router and click on LAN. Set the router's own IP address to 192.168.1.1 and the DHCP range should automatically match that range upon reboot.

I may have missed something so just in case:

If OP's network devices are looking for the DHCP Server at 192.168.1.2 (per the original 66U) then changing the 82U to 192.168.1.1 will lose connectivity for those devices.

Just following up to be sure about things.

 

[gggplaya]

I may have missed something so just in case:

If OP's network devices are looking for the DHCP Server at 192.168.1.2 (per the original 66U) then changing the 82U to 192.168.1.1 will lose connectivity for those devices.

Just following up to be sure about things.

The problem was the new router was in the range of 192.168.50.x and he wanted 192.168.1.x.

He wants the DHCP range to be 192.168.2 to 192.168.1.250.

So the router will be 192.168.1.1 and the DHCP allocation range will be 192.168.2 to 192.168.1.250 and he has a device with a static IP of 192.168.1.251.

Everything should be fine. The client devices will adjust to the gateway of 192.168.1.1.

 

[Ralston18]

My network setup is that my router is 192.168.1.1 and I allow that router to assign DHCP IP addresses in the range of 192.168.1.100 to 192.168.1.110.

Static IP's on my network are in the range of 192.168.1.2 to 192.168.1.9 (Reserved).

So my DHCP IP network devices are configured to go to the DHCP Server at 192.168.1.1 and request a DHCP IP address and the router in turn provides an available DHCP IP address in the range 192.168.1.100 to 192.168.1.110.

Here is where I am getting confused:

"The client devices will adjust to the gateway of 192.168.1.1"

How or what happens on those client devices to make that adjustment?

I really do not want my network client devices adjusting to and connecting to some other router/gateway that happens to appear on the network.

 

[gggplaya]

My network setup is that my router is 192.168.1.1 and I allow that router to assign DHCP IP addresses in the range of 192.168.1.100 to 192.168.1.110.

Static IP's on my network are in the range of 192.168.1.2 to 192.168.1.9 (Reserved).

So my DHCP IP network devices are configured to go to the DHCP Server at 192.168.1.1 and request a DHCP IP address and the router in turn provides an available DHCP IP address in the range 192.168.1.100 to 192.168.1.110.

Here is where I am getting confused:

"The client devices will adjust to the gateway of 192.168.1.1"

How or what happens on those client devices to make that adjustment?

I really do not want my network client devices adjusting to and connecting to some other router/gateway that happens to appear on the network.

DHCP (Dynamic Host Configuration Protocol) doesn't just serve up the IP address, but also the total configuration including DNS server address, netmask and gateway.

So perhaps if a client is already running, it's possible it won't pick up the new configuration until after the client lease expires and gets renewed. Or typically, a user will restart the client device to get it operational, at which point the DHCP will update it's configuration.

Static IP addresses require the admin to hardcode all of that anyways.

 

[Ralston18]

Yes: routers do many things.

The new 82U router must be configured with all of the rules necessary for OP's network.

That includes the allowed DHCP IP address range, the static IP addresses (MAC reservations), port forwarding, security, parental controls, lease times, logging, etc..

All current network devices have been configured to go to 192.168.1.2 as the router with those configurations.

If the network devices somehow find and/or go to 192.168.1.1 they will not get the necessary information. Or even incorrect or malicious information....

And allowing client devices to make such adjustments based on some discovered router would be a serious security matter.

= = = =

Footnote: with both routers being ASUS the original router's configuration settings may able to be saved and exported to the new router.

https://www.asus.com/support/FAQ/1001376/

 

[gggplaya]

Yes: routers do many things.

The new 82U router must be configured with all of the rules necessary for OP's network.

That includes the allowed DHCP IP address range, the static IP addresses (MAC reservations), port forwarding, security, parental controls, lease times, logging, etc..

All current network devices have been configured to go to 192.168.1.2 as the router with those configurations.

If the network devices somehow find and/or go to 192.168.1.1 they will not get the necessary information. Or even incorrect or malicious information....

And allowing client devices to make such adjustments based on some discovered router would be a serious security matter.

= = = =

Footnote: with both routers being ASUS the original router's configuration settings may able to be saved and exported to the new router.

https://www.asus.com/support/FAQ/1001376/

I think you have static IP address confused with DHCP reservation. They are not the same thing.

A static IP address is something you manually configure on the client device. You have to configure it OUTSIDE the DHCP allocation range. In this case the OP ended their range at 250 and so they assigned a manual static IP address on their client of 251 to be just outside their DHCP server range. When you set a static ip, it's done on the client side and you have to specify the IP address, gateway, dns and netmask yourself.

A DHCP RESERVATION is simply a pre-defined assignment of an IP address to a specific MAC address. Meaning, the DHCP won't give away the specified IP address to any other client other than the MAC address specified.

When a client first boots up and connects to a network, the client will send out a DHCPDISCOVER message. The server hears the discover message and will give the client a configuration(IP address, DNS, Gateway and netmask) that'll allow them to connect to the network and the internet. If there is a reserved IP for that client, the DHCP server will assign it, if there is no reservation the DHCP will assign it another IP address within it's allocation range, in this OP's case somewhere between 192.168.1.2 and 192.168.1.250.

That said, with a DHCP reservation, you're only predefining the IP address. The DHCP server will still give it the same configuration information for gateway, dns and netmask as it does to other clients. So once your reserved client boots up and connects to the network, it will send out a DHCPDiscover message. The DHCP server will respond with it's IP address, gateway, dns and netmask, the same as other clients. The only difference is it will get the same IP address every time.

In a typical home router, the IP address of the router/gateway is 192.168.x.1 and the DHCP allocation starts at 192.168.x.2 or 192.168.x.100 depending on which router you buy. The allocation range ends with whatever range you select. If you want 50 clients max, it'll be 192.168.x.2 to 192.168.x.52 etc....

In the OP's case, they said their DHCP range is 192.168.1.2 to 192.168.1.250 so their router has to be outside of that range. So you set the router to 192.168.1.1. Most routers will never allow you to assign the router IP within the DHCP allocation range.

In the OP's setup:
Router/Gateway: 192.168.1.1
DHCP RANGE: 192.168.1.2 to 192.168.1.250
Static IP possible range: 192.168.1.251 to 192.168.255

 

[Ralston18]

@servalan

What is the ASUS AX82U router's current configuration and what is and is not working?

Did you make any administrative changes to the router or perhaps a factory reset?