Cannot disable DHCP on my Switch?

[alican]

Hello Everyone,

I have a very strange problem with my one of my MS120-24P switch. It's giving away DHCP leases and I can't find a way to stop it. There is no DHCP configured on the switch but it's handing out DHCP leases from the 10.0.0.0/8 range. 

• My 1st switch is behaving normally. I've been using it for over 6 months.
• If I plug in my 2nd switch, it messes up my entire network within few hours by handing out the wrong IPs
• If I unplug the switch and restart all devices that got the wrong IP, everything goes back to normal.

Here is a screenshot from Switch > Configure > Routing & DHCP settings. There is no DHCP configured:

I reached out to Meraki support about it but they were not able to figure it out. I have proven to them over and over again that DHCP is coming from the switch2 but we are not able to get anywhere with Meraki support

My network setup is very simple. I've got;

• MX64 Router
• Two MR33 Access Points
• Two Meraki Switch
• I have 5 simple /24 subnets and that's it. All DHCP is managed by the MX device.

Resetting the switch back to factory settings didn't solve the problem. I re-configured the 2nd switch many times but didn't go anywhere. Switch config is up-to-date firmware is latest

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It's so sad that I dumped a lot of money into this gear and it's behaving unusual and support can't help.

I've been managing different Meraki environments for over 5 years and have never seen anything like this. Both Meraki support and Meraki devices let me down. I am very sad...

[cmr]

@alican agree it is odd as the MS120 range doesn't support being a DHCP server...  A few things I'd try that you probably already have tried:

Set up an interface on the switch in a 10.100.x.0/24 subnet, does it still give out 10.0.0.0/8 addresses?

If the switch is plugged in elsewhere, say at home, does a client connected to it get an IP?

Is the switch reaching the internet/cloud and if so what IP does it show for public IP?  It seems to me to be in setup mode, or something similar.

[Aaron_Wilson]

That's what I would try first, booting it isolated to see if it's handing out IPs with no up/downlonks.

[ww]

Can you block that mac address  so that it cant give out dhcp.?