MX clients can't connect when using a static IP

[Macauley86]

I have a small site with an MX64, MS225, and an MR42. The MX is the DHCP server. All good till we had a power outage, after which all my devices set up with a static IP went offline (ESXi host and all its Windows server VMs).

Once I switched them to DHCP, they all came online. If I switch any of them (or any Win10 workstation) to a static IP, it immediately goes offline and comes back online when switched back to DHCP.

Any advice on how to get static IPs to work again?

Thank you.

[NolanHerring]

Can you show an example of a client using DHCP, vs STATIC so we can compare. Might be something like subnet or gateway missing/incorrect.

Do the static ip exist via manual configuration on the end-device, or are you simply doing a static reservation on the DHCP server on the MX instead (outside of the scope range, and created via MAC etc.)

[Macauley86]

I put a spare MX64 in, and now static IPs seem to work.

[NolanHerring]

You mean a warm-spare to your original MX? Can't see why that would make a difference. Strange.

[Macauley86]

Yes, I added it as a spare to the network and connected it in place of the regular MX64. I just tried a couple of computers (a server VM and a physical workstation) with static IPs, and it's working.

[PhilipDAth]

You haven't enabled Dynamic Arp Inspection on your Meraki switch by chance - which by design blocks statically configured devices?

https://documentation.meraki.com/MS/Other_Topics/Dynamic_ARP_Inspection

Otherwise look at the settings the machine gets using DHCP (subnet mask, default gateway and DNS servers) and make sure you are using the same values when statically configuring.  Also make sure the static IP address is not already in use.  Perhaps some other device grabbed it via DHCP after the power outage.

[NolanHerring]

Good catch Phil. Was focusing on the MX or clients, didn't' even think of that lol.

[Macauley86]

Ah, it was enabled. I disabled it. Thank you. Didn't know that.