MG gateway port forwarding and dhcp reservation for Meraki MX

[CarlT]

Hi All

I have set up a MG51 cellular gateway, this plugs into the WAN1 on my MX68 device and provides the MX with a dhcp IP.

I added a fixed IP assignment and port forwarding so it forwards VPN traffic to the MX, however I have noticed my MX didnt take the IP that I assigned it but instead the next IP in the block

The strange thing is the VPN still works to my third party firewall just fine.

Reading the below, it looks like Meraki reserves the first few IPs for MX devices anyway in the background, is this the case? is this why the VPN still works and it does the port forwarding in the background etc?

cheers

MG Wireless WAN Dashboard Settings - Cisco Meraki Documentation

[alemabrahao]

On MG cellular gateways, the LAN subnet is automatically divided into child subnets, and the MG always takes the first usable IP of its assigned child subnet. This behavior cannot be changed.

The port forwarding on the MG is based on its DHCP assignments, not on the specific IP you intended your MX to use.

[CarlT]

Hi,

its not the MG Gateway I have question on, its more how does it apply DHCP to MX, from what I can see it reserves the 2nd/3rd IP of the subnets for the MX appliances

[alemabrahao]

Meraki does NOT reserve the second or third IP address for MX devices. What you are seeing is simply that the MG always receives the first IP and the MX is usually the first DHCP client.

Therefore, the MX receives the second IP (or the third, if the second is reserved/unavailable).

This is normal DHCP operation, not a Meraki-specific reservation mechanism.

[PhilipDAth]

I haven't tried this, and I give you a 1% chance of success, but try:
https://developer.cisco.com/meraki/api-v1/get-organization-clients-search/

It returns lots of information about clients in the network.