DHCP assigns IP's outside of range

Technical Support for Routers
1

Hi, I have a Flint 2 that is assigning IP's to devices outside of the range its supposed to.
Basically, I have my subnet mask at 255.255.0.0 because I want to have specific devices on a subnet like 192.168.10.X via static ip, but I made it so that the routers DHCP should only give out IP's to devices from 192.168.1.10, up to 192.168.1.250, and that the only way that they should have an IP on any other subnet besides 192.168.1.X is if I manually set a static IP.

Despite this, I have some random devices like my google home and other devices that are on the 192.168.10.X and 192.168.0.X subnet that were supposedly given out by the routers DHCP server, even though its only supposed to give out ips on the 192.168.1.X subnet. I never configured these devices to have a static IP, so the routers DHCP server must have done this.

How do I fix this issue? I have tried resetting my router over and over with no success.

Here are some images to show the issue:

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Screenshot_20240905_080918_Chrome
Screenshot_20240905_080931_Chrome
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Screenshot_20240905_081000_Chrome
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Thank you

2

Hi, try to connect and with command line:
cat /etc/config/dhcp
check and send here the following:
config domain
.
.
.

config dhcp 'guest'
option interface 'guest'
.
.
.

also check if you have any of the following, that give a static IP:

config host
option mac '??????????'
option ip '192.168.45.170'
option tag 'NAME'

3

How are you verifying they were "supposedly" being assigned by the router's DHCP process?

On the router, look at the /tmp/dhcp.leases file and see if those IPs are in there. That should be a record of all DHCP addresses that were assigned by the router DHCP process(es).

4

image
image1456×438 125 KB

This is what I see when I check that file
How I verified it was that at any point, I had never put any device on the .10 subnet manually, which is how any device should even end up on that subnet, by me manually adding it to it
I also traced down one of the devices, (192.168.10.22 in the client list) to be one of my smart light siwttches, which I don't even know how I would give a static IP, so I don't know any other way this device got an IP on the .10 subnet, and it didn't appear on the file, yet its still active under that subnet.

5

Screen Shot 2024-09-05 at 5.54.47 p.m.
Screen Shot 2024-09-05 at 5.54.47 p.m.1140×1716 215 KB

Heres the entire configuration

6

Hi, it seems to me that the configuration for the dhcp 'lan' is not correct, if you check the"
option start '266', as per documentation:

"Specifies the offset from the network address of the underlying interface to calculate the minimum address that may be leased to clients. It may be greater than 255 to span subnets."

have you done some manual configuration there?

the following is the documentation for the dhcp:
https://openwrt.org/docs/guide-user/base-system/dhcp

check and let us know.
cheers

7

Well thats what im confused about, but that's what GLinet is doing apparently when I set the subnet mask to 255.255.0.0 and the range from 10 to 255, if in luci I change it from the bugged out value to 10 to 255 for the DHCP server, the glinet configuration breaks

8

It does not make any sense to set the subnet to 255.255.0.0 - don't do it, use proper subnetting and routing instead.

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