Error: Gateway should not equal network ID when configuring static WAN IP address

[MB3]

First post here, 10+ year Meraki user. 

Context: I've got a new error message I'm not familiar with, and can't find any mention in the SDWan troubleshooting documentation. I'm attempting to establish a new staticIP address for an MX68 appliance that is currently in a double NAT situation.

Attempt: In the past, I simply would use the uplink tab, change the WAN1 config from DHCP to static, input my static info and wait for the changes to synchronize. In doing that today I'm receiving an error message: Gateway should not equal network ID

Confirmed GW, Static IP, Subnet, DNS1 and DNS2 are correct from ISP.

There are no VLAN's utilized. 

The second WAN port is disabled.

[ww]

Sounds like your using the first ip of the subnet as gateway, for example the x.x.x.0 from a /24 Whats the gateway ip and what is your subnet mask?

[Brash]

As WW said, the error indicates that the IP address you're using for the gateway is actually the network address (the first address in the subnet). This is always a reserved and non-assignable IP address.

A good way to verify this is by using a subnet calculator:

IP Subnet Calculator

[MB3]

Finally got through to support (75 minute wait time) and they were able to confirm the same thing. It sounds like I will need to program the static IP at the local config page instead of through the dashboard as @ww  is correct, the first IP of the subnet is what the MX is showing as the current public IP address, even though the WAN address is a local IP. Headed on site to make the change now. Thank you! 

[Bruce]

@MB3, what subnet mask are you using? Just be aware that if it’s a /31 (which should work with the MX), then the MX has to be higher of the two IP addresses. Not sure if this is the case, but just a heads-up in case it is.

[MB3]

On site, connected to firewall over LAN (wired.meraki.com) and set the static IP settings on the local device. After an automatic reboot cycle, local indicated all good. Dashboard took 10+ minutes to update. Checked to make sure DNS was correct. Internet traffic is up and testing fine, but dashboard continues to say bad IP assignment even after configuration synchronized with Meraki. Static IP settings on the dashboard indicate MX WAN 1 is still pulling a local IP (192.x.x.x) and dashboard says "Bad IP assignment configuration". If I click edit on the WAN 1 configuration, my static IP settings are there. 

I think I've seen this in the past - the resolution was to remove the firewall from the network and re-add it to force an update. I'm hesitant to do this here though as the appliance is passing internet traffic just fine. 

[MB3]

Let it sit for 24 hours and the 'bad IP assignment' hasn't cleared itself, but network remains online.